It's your car so you can do what you want with it, but I am not a fan of anything larger than 17's on an E36. That being said there are loads of wheels that look good on a ti. My recommendations are the following:
17" - DSI (OEM wheel)
17" - Style 42's (2 piece OEM wheel made by BBS)
17" - Style 19's (OEM 2 piece wheels made by BBS)
17" - Style 5's (OEM 2 piece wheels made by BBS)
17" - Contours (OEM staggered wheels)
17" - Style 32's (OEM staggered wheels)
All of the above wheels can usually be found on Craiglist / BMW forums / Ebay. They are well made and will give your car the coveted OEM + look. Another helpful site with a decent selection is Tire Rack, and you can see how the wheels they sell will look on your car.