You know you could make one. You can get cheap digital scales for like 20 bucks a piece and then you would only need to get a nice 1/4 thick piece of plexiglass and mount the scales on their and maybe a small level to check to make sure eveything is level. I have seen a few done this way.
The IRS on though is killer. I thought of getting the 2 scale setup sometime unless I could get a steal on the four scale version.
Castle Creations (Since 2005)
Bumps & Jumps RC (One of the best racing facilities around)
ST Racing Concepts (STRC) Great aluminum upgrades for many brands.
Custom Works (Best Oval Cars around). Too many titles to list
Shout out to: Sticky Kicks, CR Graphics and Race Ready Products