Give the demo a try. Most moderately detailed levels get over 200-400 fps. More than suitable for an indie game. I have a little work to do before I can release the source code, but you can get a head start on by downloading the demo and testing out your own levels with it.
I just added support for Quake 2 levels this week, but I've also added support for GoldSrc as well, so Half Life and Counter Strike maps will also load.
For some test levels, I would go to slipseer.com and download some of the community map jams. There are hundreds of maps to play with and many of them are really great looking. You could also buy the Quake Rerelease on steam pretty cheap.
