I have an E30 that I bought for use as a track (drivers school) car. It had been previously used for autocross and has some no name plastic bucket seats. These will not pass tech for a drivers school so I am wondering what kinds of seats others are using, taking into consideration a budget. What is the spec rating for seats?
If budget is a concern (and it always is), you should seriously consider aluminum racing seats. You can get them made to measure and the price is very fair. Best of all, it's very easy to add a back brace, which greatly improves how rigid the seat is: you really feel what the car is doing when you've got little to no flex in the seatback. The most popular options are Kirkey and Ultrashield. Personally, I really like the Ultrashield "Rally Sport" seat: The sides are a little lower, which makes it easier to get into and out of the car. Plus, it's easier to use your stock 3-point seatbelts. The price (including a solid-colored seat cover) is just under $250. It's a very good deal.
In consideration of seats, check with the organizers. Chapters have different rules when it comes to restraint systems.