M.M. Weapon Suggestions Needed

Whilst playing a M.M. round, I began thinking about weapon choices. I play M.M. often, and I think I should have a gun to reflect that. In all of my extensive crossfire career (just under one month [LOL]) I had never given thought to which gun could be the 'best' for multipurpose fighting in mutation mode.
Being the scholar that I am, I decided to converse this matter with my peers on the forums. After checking out a few threads, I found many rather varying oppinions on what exactly the best M.M. gun is. Question still in mind, I determined that the best M.M. weapon would in all likelyhood be a ZP weapon. However, before mindlessly tossing more (yes, more [I have had bad experiences with the black market...]) money into the game, I thought it prudent to find out how much I would need, approximately.
I hit a brick wall here, though. I didn't even know what weapon I would need, from crates or otherwise, much less the average cost/probability of crate success. So I come to you with one humble request: That you would tell me which weapon to get. Please include in your post about how much ZP I'll need to purchase your suggested gun, if you know it.

Information you may need:
Current VIABLE guns include, but may not be limited to: M4A1-C, AK Silver, MP5(k)-ADV, and a great number of varying TEMPORARY assault weapons that I would rather not use.
I dislike glitching, although I can if need be. I prefer camping at a defensible site with a few friends; the problem is that, should one of them be the mutant, I would like to be able to run away, or at least have enough ammo to get away with considerable damage dealt. (not necesarily escaping)
I ussually play at port.
I would also like suggestions concerning sidearms.


I am aware that there are other threads on this topic, but none of them (yeah, I checked the forum's search engine) 'answer' this question. Some of them even wait until the end to say something like "your weapon choice really depends on which weapon you like best", or simply pointing out the pros and cons of each gun, leaving you with no suggestion, no personal preferance. They don't even establish a ranking system or general idea whether, say, the accuracy and mobility of gun A will outweigh the high ammo of gun B, or the power but recoil of gun C puts it above the blatantly low power, recoil, and knockback of gun D. Obviously, a clear winner ought to be chosen for such a unique mode of gameplay.