Hernando - well there are several brushes that will do the job just fine... the Badger 175 and Badger 155 would work fine AND if you ever decided to do aircraft would go into the smaller scales easily... The Omni 4000 is a nice brush as well and being gravity fed it will get you greater detail which might come in handy with figures at some point. Probably the detail brushes like the Badger 100LG would be too fine of a spray unless you bought a medium tip for it... 1/35 armor would require a wider patter for a uniform coat.
I have both the 175 and 155 by Badger and love them both... to be honest I think the 175 does better at large coverage, and with the fine needle (which if you buy the comlete kit it comes with that and the airhose in addition to bottles and metal color cups) you could do smaller detail like shading and such on figures (probably, I don't do figures so I am just guessing) it has a wide body about like a medium cigar, the 155 is more like a thick pen... so depending on what your hand size is and how you think it will feel to you either one is adequate for what you do. The 155 does good at a wide range of coverages all with one needle. It is also easier to break apart and clean..
Either one would cost you about $60 (ish) for the set with the airbrush hose etc.. (www.dixieart.com is great and has free shipping on orders above $45)
Now for an air source you will probably want a compressor as it is SO much cheaper in the long run... if noise is not a problem, i.e. you dont live in an apartment or with people who would be bothered by it... Wal Mart, Lowes and Home Depot all carry compressors more than adequate for the job... all for about $69 and up.. you will need a regulator and watertrap for about $30 more total...
When you order your airbrush order at least one extra needle... it would suck to bend the tip on one and have to wait for UPS to bring you another one and you'd have to wait in the meantime... Needle lube is a high priority item as well, especially if you spray acrylics.. it helps keep paint from adhering to the needle and makes them easier to clean... both needles and lube are about $5.00 each...
Wel I wont ramble anymore... if you have any more questions feel free to ask! there are more airbrushes that will do what you want out there, I just mentioned the ones I am familiar with.. if one interest you come back and I am sure someone here has one and can answer your questions!!!