Skip 2.1 and go right to 2.2. Froyo is great!
Ok, to be fair, in order to install Froyo, you're going to have to first flash one of the "official" 2.1 updates anyway. Your choice really, but I tended toward the Swedish Tre rom while I was using 2.1. When I decided to bump up to the currently available CyanogenMod 6.1 mod for Pulse (still in beta), I went back and flashed the UK 2.1 rom as a base to start from.
I still have no idea why the UK 2.1 rom was pulled. But I'd highly recommend the latest FLB mod of the UK 2.1 if you want to hold off on Froyo to get the final bugs ironed out.
All of these mods are available over at MoDaCo.com.