I dunno if I'm too late or what, but before you go spanking a load of money on a vest or chest rig, before you've decided what sort of loadout you want to go for, maybe get something 2nd hand to be going on with? You'll get some idea what you want from kit that you buy later.
US Issue Style Vest - ignore the title of this auction, this has nothing to do with the SAS or any special forces, it's US Woodland pattern camouflage and the vest is made to carry 6 M4 STANAG mags and 2 grenades - it's lightweight and fully adjustable.
South African Style in black - you can get this style of vest in just about every type of camo and the more common ones are cheap as chips 2nd hand (the seller is living on cloud 9 putting a B.I.N. price of £30) -
Here's 1 in DPM - you can get 12 STANAG mags just in the pouches designed specifically for them, then there's another front pouch which is described as utility which is the right shape for another 4. There are also 2 grenade pouches on the front, high up so they would be ok for a phone or radio, etc., plus 2 huge utility pouches on the sides and a double hydration pouch on the back - again fully adjustable.
Both of those vests would hold mags for G36, G3, SIG 552 & variants, Steyr AUG as well as NATO STANAG but not AK, MP5, M14
British Army Style - you can get 12 STANAG mags in the front lower 4 pouches, but also they will take just about any mag there is, even long thin mags like for the MP5 (tommy gun even!) because the flaps have sides and buckle down, 2 side pouches that can take even a 58 pattern water bottle & cup or just your gloves and 2 upper pouches that you could stuff with more mags, but will take pyros, your phone, radio, fags, lighter, sweets/chewing gum, tissues, speedloader/s, BFG/s, etc.
Here is another one in better condition - ignore the title obviously (how anyone could think this is desert DPM is beyond me lol! - I've got one of the Marines varient of these and it's really comfy -
like this and
here's the same type in DDPM
This last one is a sort of
hybrid British Army Style & Molle Platform and is a bit more expensive than those above (lol)
Edit to add: no I can't leave it alone yet -
HERE is a DDPM Molle Vest & Pouches - check the price lol!
and HERE is a
DPM Molle Vest & Pouches - more expensive but still not bad.