If you just want a stock one, you can use the Nissan Patrol clutch, which is slightly stronger (and fits an r33). That is probably the cheapest option if your car is going to stay fairly stock.
Otherwise, it really depends on how much you want to spend, your current and future power levels, and how you will be driving (drift, track, road, or drag).. If you can post up what you are looking for, then people might be able to give some more specific recommendations.
Generally the Exedy Organic Clutches are a good clutch up to around 230rwkw.. or something like the Xtreme clutches are also quite good at similar price / performance to the Exedy ones.
You are looking at anywhere from 300-800 for a new one though, depending on the exact type you are after.