JCWhitney has the Scanguage II for $159.99 + free shipping using code SAVENOW + a $50 JCWhitney gift certificate. Apparently, if you just go to their home page and search for Scangauge, they have 2 options. Make sure you order item # ZX530594 since that's the one that comes with the gift certificate.

 

if only i could make it work with OBDI

 

There's something out there called a SuperMID, but I can't find much info about it or where to buy one.

If you're handy with a soldering iron, this looks promising and kinda cool:
MPGuino - EcoModder

Alternately, I've not tried this (but the logic is certainly sound), a simple vacuum gauge can help you visually see how much load you're putting on the engine.
Sunpro 2" MECHANICAL VACUUM REPLACEMENT GAUGE : JC Whitney: Auto Parts & Accessories

 

good call Loren, i'll have to check that out, sounds interesting, i'm always down to tackle something

i should get the scangauge for the S though...