Beyond berliner weisse (which I do like quite a lot), I have no experience with sours. If I can make a suggestion for your first run at it, try making something using the kettle souring technique. This involves souring the stuff in the kettle before you boil it (so it sits in the kettle for a day or two warm to let the lacto sour it up, then you boil it and make it like you would a normal beer. The advantage of that is that you kill all the bugs in the boil and you don't risk contaminating your stuff. Therefore, you don't need to buy a second set of equipment.
You won't get the same complexity or whatever that people like in many sour beers (I'm not a big sour beer person), but it is a good way to get your feet a little wet and make something you can enjoy. Also, the turn around time on it can be pretty quick since the kettle souring happens in days instead of months.