Great developement! I've got an Dell Venue Pro wich is developer unlocked by myself trough an dreamspark account.
I don't know much about WP7 rom development, but maybe i can help you with testing on my Dell. I do know something about Android development.
An HTC Desire S is my primairy phone, so this Dell is for developement purposes until custom rom's are made possible.
I've already updated my device to 7.10.8107.79 and Dutch language trough the custom WP7 Update Cab Sender.