My drag kit was cheaply built. The manifold weights about 30 pounds, so you'll need to reinforce your exhaust with studs or helical-coil inserts, or you'll strip out the threads in the head. The piping is chrome-plated steel, which looks nice for about 6 months (except for the really poor welds) until it starts rusting and the chrome flakes off... and then it rusts on the inside and you get crap going through your cylinders. Nevermind the fact that they come bundled with turbonetics turbines which lick sack. I had one come to me that blew out as soon as it got oil pressure. The second one they sent started leaking oil too, and the response on it, when it did work, was super slow.
Now that I'm N/A again for awhile, my advice is to sit down and assemble a custom kit. Have the pipe (I'm going to use stainless which is more expensive, but eliminates the rust worry) custom bent and make the kit sized to your individual needs.