welcome, Adam. The place to start would normally be in the "new members intro" thread (or whatever it's called). So, to your query. The 325i you've linked to looks pretty spartan, no carpets, race seat... the seller states he's selling to build an e36 that is more road than race... inferring his e30 is more race than road. And it's listed in the Competition Cars section. WoF is long expired - and one wonders if the brakes have been certed.
Looks like a cool car, not so sure it meets your idea of "fun and zippy" and "not too much track stuff". It's probably very zippy, and a bunch of fun. It is on Koni adjustables and Toyo R888s, so it should go round corners well (ref also Hampton Downs times). We need to get an idea of what fun means to you. One man's fun is another man's agony!
Perhaps you could give us an idea of how much motorsport you're thinking of participating in?
cheers