You'll probably be best off going with the
G&P 130 Rnd mags.
I've got a similar project starting soon, picking up an M15A4 Carbine in a trade for my HK33K and turning it into the British L119A1. The project will be purely cosmetic with things like a heavy barrel and stock pad. Perhaps later on I'll cut a AG36 into the foregrip...ah plans
