I've run Chevy's w/o issue. P3 is working on some custom kernels for Sapphire which are supposed to give the best overall experience w/ Sapphire, but I think any should work as long as they are Froyo. A Bekit kernel comes with the default 0.6.2 install.
Try any you like, but I want to stress we only stand behind the current P3-sapphire kernel and the kernel we release in the rom itself. Any others you use at your own risk.