BTW, how would u be using the gun? Practical shooting, home/personal defense, just plain plinking, or simply to pet a cool piece every night? This is important since issues like the gun's ability to digest cheap, reloaded ammo becomes difficult with the polygonal-barreled HK's and Glocks. TMJ reloads are about twice as expensive to shoot than lead bullets, and forget about FMJ's if you intend to shoot often, they cost 4-5x as much.
I have not yet entertained the idea of getting a weaponlight or tritium sight for my HK, since i'm spending most of my time with it in practical shooting, so i don't think i would need those accessories (well, not now at least ) . However, you could call up our local HK dealer (Tri-Mark) in Manila at 840-4867 and look for Christina or Gary. They'll be more than willing to answer your queries as regards the HK line.