These where a one off eye ball, figure it out as I went deal so it's what ever the chances of you buying some square or box tubing and making them are. 

The 450 shocks will also fit with stock upper mounts you just run the risk of the Ball Joints being pushed out.  I know a lot of guys that run them this way for years without problems.  If you do run them this way I'd put in new ball joints just to be safe. 

I think they're like $20-25 each, cheap insurance IMHO.