Danglerb:
If you’re not in a hurry, I might suggest searching your local pawn shops, craigslist, and fleabay for used Snap On MT2500 Scan Tools. It does both OBDI and OBDII(with the correct hardware/software). I scrounged my rig in about a week, and spent right at $300 with shipping. The MT2500 ‘Brick’ has been discontinued and Snap On will no longer support upgrades. Techs are selling theirs and going for the newer, faster, hi-zoot Solus, Verus,etc. The ‘Brick’ was very popular and effective from what I’ve read, 80’s until now. The main body has a display (version 1.8,version 2.2 backlit) with 2 memory cartridge slots, one for ‘primary’(year range and car brands) and one for troubleshooting(year and brand). Most setups come with the brick, carry case, manuals, cables, adapters, some personality keys(for OBDII) Later black cartridges have proms that could be flashed by the Snap On rep with updates for $$$. You could probably get away with one or two sets of cartridges (and a personality key) for the Conti and the Stang. Do some reading on the web to make sure you understand the combos you need. When you get a different car, just scrounge up another cartridge or two. Transmission, airbags, imports, etc. are available. Hope this helps.