Royal Marines fan? Nice.
I'd also suggest the HK416 over the G3 as your first gun, and yeah VFC is pricey. They make really nice stuff though.
If you haven't already, I'd also put some thought into gear: plan on playing milsim? Low caps? You'll need something to carry the mags. Plan on doing a specific impression? Once you start adding armor, MOLLE pouches, etc... that ads up, too.