do you want to build it yourself or buy a standard one? if so, I would look for a 2nd hands playseat. 100 pounds isn't really much to buy a standard playseat, so I would go and try to make one myself. Í only am 16 years old and have a low budget too. Because of that I made my own seat. it became a nice and really study racing seat.👍
sorry for bad English, I'm from Holland