Techstream for 1st Gen's. How much can be done?

For any 1st gen'ers out there that have TechStream & a mini VCI cable, how much functionality is available in the app for our rigs? More specifically, for the pre-2000 trucks (mine's a '98 3.4 4WD MT).

I'm considering getting a mini VCI cable w/ TS mainly for doing engine diagnostic work & being able to see the extended Toyota PID's, 'hidden' on-board monitors, and to have the 'Active Test' feature (to activate fuel pump & stuff like that).

Since I realize that my model year is pretty basic, I'm not expecting to be able to do a bunch of customizations or ECU reprogramming. I've read about ppl doing for the later years (changing door chime, wiper speed, etc.), and I don't really care about any of that.

The only other 'advanced' feature that I might be interested in would be the Airbag codes & info, but I'm not even sure if that would be available for my truck through TS.

Also, I've seen some discussions about different versions of the VCI cable having different features & limitations, and so the guys that are planning on doing more advanced stuff, like ECU reprogramming, need to be careful about which cable they get. But, since I'd only be using this for the most basic stuff on a '98, should I just be able to get any 'ole vci cable, or should I still try to aim for a specific type/version?