A good compromise if you want a decent bump helmet but don’t want to shell out the £600+ for an ops core is the EON carbon composite helmet.
Carbon shell like the ops core and comes with 4D pads, real Wilcox shroud too.
Suppressor mount, B&T or LPE.
B&T railed forend for the SD, Wiitech make one, I have one inbound.
Gibbous outfitters do a rather nice mount that goes around the front sight, including a mount for your switches.