Choose any database you want. Tapestry is simply AMAZING!!! Everything is a component. It is like have all of the coolest legos and building sites in not time. Also, if you don't like the block, it is EASY to make custom components. Howard Lewis Ship is a genius.
Okay, the Java world needs to really wake up and start buying into Cayenne. Get off the Hibernate kick!!! All I see is ways to improve Hibernate and Cayenne already has it all in place. Plus Cayenne and Tapestry were made for each other.
J2EE was a nice try, but way, WAY too complicated. Both Cayenne and Tapestry are straight-forward and easy to use, IMHO!!!