I know a lot of folks want a certain look, but that'll end up costing about £160-70 when it gets here. You can go on Brownells UK and buy some reallly decent RS AR forends for less money than that; ALG Defense in particular are Geissele quality, but there's YHM and Remington on there for sub 170 too. Or for just a couple of notes more you can can get some excellent Midwest Industries freefloats which will be immeasurably better quality than madbull. Probably no more involved of a process to get fitted to any given airsoft gun either in the grand scheme of things, taking all factors in to account.