This mod alone convinced me to buy San Andreas for PC. The game makes a lot less sense this way, but on the flip side it's hilarious (beheading fairies, Ibuki Gourd grenades, strange dates, being able to eat 10 large pizzas at once without any fat gain, etc.)
I also have the Steam version (running on Windows 7 64-bit), and for those of you having problems with it you'll have to replace the "gta_sa.exe" with a modded version 1 executable (not helping here). No need to move the San Andreas files to another directory - I have my install running from the default Steam one, and it runs properly from the Steam launcher. Models, spellcards, etc. work properly.
Also, Steam version users will need to use version 2 saves, even though a version 1 executable is used. Version 1 save games will crash the game - different file and memory addresses perhaps?
Lastly (for any version of this game), switch to the CJ model when trying to improve muscle, fat, or lung capacity. This is already implied in the included readme, but it took me a while to figure out why my character (usually Marisa, Cirno, or MoF Aya) would not get any stronger after a bunch of gym sessions, or why they couldn't gain more breath after swimming around San Fierro.