For OBDII, the scangauge II is the best.
www.scangauge.com
there are group buys on many forums, you should be able to find them for 140-145$ US shipped to the lower 48.
There is one on customtacos, and might be one on yotatech.


89 4Runner
3" BL, M/T locks, 33"bfg mt, bilstein, Kayline, tubebumper, toyotafiberglass panels
TBI: Elocker,3.4 w/ORS,b+b,S2Sstg2cams,arias pistons,P+P intake,TRDs/c,URDpullies+7th,downey headers,MAPECU2,WEGO WB, SupraMAF,walboro255,stg4clutch, EPaOo2 sim