Call up these guys: http://ajeracing.com/ See if they have any more slightly used ones. I got a great deal on one shipped to my house. Should be installing it very soon.
If I hadn't went this route, I was leaning towards the chromoly of UPRs.
I just bought a K member and while I was doing some research, I heard of people having fitment issues with the QA1 piece. The MM piece is probably the best one you can get, but it's $$$. I went with a PA Racing K member and A arms which will hopefully be here this week. I got some good reviews from people on these boards and the price was right.
THe QA1 has some issues where it moves the front wheels forward a little, not really a problem for a race car but for a street car it has presented some issues. I have had really good luck with the UPR and the AJE.
I had the QA1. Mine bolted right up, no problems. Only issue I had was the car was lowered way too much after the install. I had to put 1 inch rubber isolators under the front springs. Green 94 5.0 (Roger) had the same issue. No biggie they were $10 each from Steeda. The stock A Arms will work if you grind down around the rubber housing. I used a cutting wheel ($10 at Harbor Freight) with my air compressor. Took no time.
Truthfully, it's not worth getting a Tubular K-Member if its a daily driver or a cruise car. The only thing it's good for is the headers have lots of clearance. Other than that to me it's not worth the money. Yeah it saves a little weight but it's not dramatic if your not drag racing it often.