I'm fairly sure you need SafeStrap to install the Eclipse ROM, and you can not have BootStrap and SafeStrap on your device at the same time. I might be wrong, but that was my understanding when I started reading on the subject.
You should be able to flash either SafeStrap or BootStrap using Matt's utility tool (1.81 is the latest).
.211 and .215 are very close with just a few bug fixes (but since it's not been pushed I'm guessing they are working on other fixes before pushing another new ROM, which usually means a different version number before it's released)... I would think you should be able to use either, but be sure you have backup of your Stock ROM. I'm currently running Eclipse 1.2 ROM using SafeStrap over the top of my stock .211 ROM.