High Speed Gear Wasatch, Wesatch or Woosatch, depending on your desire.
The Wasatch works better over the IBA. The Weesatch is smaller (chestwise) and the Woosatch has no internal magazine pouches so you can set it up as a custom rig.
HSG khaki is a close match to 'official' USMC coyote brown. Lots of Lejuen Marines have bought these.
Check with your unit chain of command as to what personal gear is allowed. Some units allow it, some allow certain items, some require you wear what's issued and nothing else, and some require you wear what's issued and nothing else - and you'd better have it exactly by the SOP. Nothing like dropping big bucks on kewl-guy nylon and then being ordered to wear 782 gear "IAW the SOP".
The Specter MOLLE / PALS version is based on their Mk I, which carries 3 magazines. It has enough PALS webbing to attach what you want using some combination of shingles and pouches, but you'd have to triple-stack your magazines to get 12 (think having that in ftont of you, especially in the prone).
Serious-use tactical nylon is personal. Post and intro in Crusader's Hall and then ask in the Second Line forum on LF forum. Serious non-airsoft poseur, non-wild-eyed armchair SHTF commando-wannabe questions get serious answers there (even non-idiot airsoft questions asked respectfully get answered).