188.8.131.52. is the most recent version
To run scripts you'll need scripthook and an asiloader (dsound.dll or xliveless.dll). To install vehicles/weapons/player items you'll need OpenIV or SparkIV (but you probably already knew that).
For some links and a good first script to start with I'd suggest downloading this: http://www.gta4-mods.com/script/simp...rsion-64-f2115
There are some links to files you need in the readme, and the trainer itself is really fun to use and quite handy