go to www.airsoft-war4.com and search m11 in the search box.they have the CQB kits, in black and chrome.they also sell the magnesium bolts.metal tops, bottoms, silencers, and the full metal kits.also they sell the rail system and a supressor in one package

I went over to that site and the black CQB Rail kit was out of stock, but it said the silver one was in stock to my surprise! of course once they received my order for the silver one they realised they were out of stock of the silver ones too

I've tried every major retailer of G&P parts, and nobody sells the rail kit anymore

On a better note, my G&P M11A1 steel kit should be here today! I've never had to take the internals out of the lower receiver, so I hope its not too difficult!
Also regarding the M11A1 reliability, the issue like someone said above, is the plastic nozzle on the bolt getting stuck. Its a very tight fit, and often sticks in the "out" position while firing, which jams the gun.
I've also experienced, when clearing a jam, the loose bb's getting stuck in the lower receiver internals, which is hard to see if you use black 6mm pellets. A freind of mine's M11A1 stopped working, and he gave up on it. Turns out he had a black 6mm pellet stuck in the internals. we popped it free, and the gun worked again, LOL!
I've also been using a thicker viscocity silicon lube (G&P Cylinder oil) on the metal bolt and moving metal parts. I just put a hefty amount on my fingertip, and spread it manually over the bolt, and inside the upper/lower reciever. This seems to provide better movement of the parts than using the spray silicon lube in a can. The spray kind tends to be too thin for some bolts, and will still allow metal to grind itself thinner.