Gear

Gear, to some extent, is individual.  I don't go completely by the military standards for gear, mainly because one size may fit many, but not all.  Remember gear does NOT replace being fit and in shape.  If you can't move, you will be ineffective.  Get regular pt, preferably every day of the week, and get your diet to where you will be able to maintain being fit.  Gear also does not replace training either.  If you don't use your gear, you will be unfamiliar with it when the time comes.  Plus, if you don't use your gear, you wont knows the weekness' of it as well as what needs to be fixed for you.  Plus, if you loose weight, gain muscle or many other things, it will need to change, even if ever so slightly.
Radios:
For hand held radios, right now, I prefer the Baofeng UVR dual band Radio with a better than stock antenna, like this 7.5 inch antenna or this antenna.  I prefer the UV-5R primarily because of the low price and it seems really durable. It is a dual band radio, it works on the 2m and 70cm, roughly 144 mhz and 420 mhz ranges, vhf and uhf.  It can be both programed with a computer or manually.  Manually can be difficult at times, and sometimes hard to figure out.  With the longer and a more durable antenna, my  UV-5R radio has been able to reach repeaters approximately 20 miles away.
Another decent radio is the BF-888 from Baofeng, it's lower in price, but it also has less functionality.  It only is able to work on the UHF 420 mhz band.  It can only be programed via the computer cable for the radio and only has 16 channels to use and can't have a frequency manually input.  It is compatible with most frequencies that are being used, except for the murs frequencies in the VHF area.  MURS is the multi use radio service, which is the least restrict as far as power antennas and who can use them.  A few members of the Arizona 1st Pathfinders use this radio
The UV-82 seems decent, but I don't have any first hand experience with it, nor have I seen it.  It has an expanded UHF frequency range, but is at least $10 more than the UV-5R.

Clothing and shoes:

Get a good pair of shoes, this is really important as your entire body rides on your feet and ankles, make sure they are adequately supported.  This usually means no big box shoes from the local cheap place.  Make sure that your clothes blend in to where you will be working.  When I'm in the desert, just camping or such, I use something that's close to the color of the desert floor.  Get clothing that is as quality as you can, but don't go crazy.  As with anything do your research.

Weapons

I suggest having a long gun and a sidearm, with the long gun being primary and the sidearm being the secondary.   Ar style rifles have their places as do ak's, mosins and similar weapons, I no longer get into the which gun is better debate.  It's usually a preferance and which weapons and ammunition are most widely available, both in emergency and non emergency situations.

Recommend at least five reloads for the primary weapon if it is a rifle, I have not used a shotgun for a primary, because it is so close range and so wide of a shot, unless using slug rounds.  Also, at least 2 reloads for the secondary weapon.  The shotgun can be used in a team/squad formation as a close range weapon, but it's not really a long range weapon, at least in my opinion.

Make sure that you regularly inspect your weapons, even the most reliable and the weapons that need the least cleaning, still need to be cleaned occasionally.  The AR15/M16 style weapons do need to be cleaned, even if just a wipe down and re lubricated.  They should be cleaned, even after only firing a few rounds.

Water:

Water is the thing that the human body needs the most besides oxygen.  It is very important, especially in the desert, it gets really hot, as anyone who lives in the desert, or every been deployed to one.  From vets that have served in the middle east or other deserts, they say it gets extremely hot.

Some sort of water bladder is necessary.  Even thought most teams use something similar to a camel pack, they still carry at least one canteen on them as a reserve.  Get a reliable and rugged way of carrying water.  Also, learn how to acquire water while in the field.  This very well could save your life.  This also goes into fitness.  The more weight you carry as a result of fat, means the more water you will need.  While more beneficial than fat, muscle is much heavier than fat.  More gear also means more weight, which can result in increased water requirements.  I suggest some short of pack that has a bladder area within the pack so that you can put a bladder in there.  I suggest something with a quality bite valve so the water doesn't leak out, you want to use that water, not give it to the plants.

Food.

While out on shift type of patrols, I don't carry a lot of food with me.  I carry no more than two days worth of food on regular daily patrols.  Mainly as a just in case method.  Start learning the edible/non toxic plants and animals in your area, so that you can get food in a pinch and to extend your food supplies in a long term mission.  Make sure the food is actually nutritious.

  Here are a few products that have come in with decent reviews and that seem to store well:

      Chef's Banquet All-purpose Readiness Kit
      Chef's Banquet Freeze Dried Fruit Variety Bucket-300 Servings
      Chef's Banquet Freeze Dried Vegetable Variety Bucket-320 Servings