I've had some very spunky female Bettas in my 46 at different times and I loved to watch them wriggle in and out of the Java Moss. One liked her own little cave and another I used to have actually jumped through the food ring to scatter the flakes!
I can't wait to see some pic's of your handsome new male. I think you should pick a gravel color that you like that would make a striking contrast with the white of the fish. I also liked the moonlight idea that was just posted.
I had a 20 gallon split into three separate sections at one point for Betta males. It looked neat, while it lasted, but unfortunately the gravel I used leached something into the water and killed all my guys.
I now have the same tank full of guppies and haven't been brave enough to try Bettas again yet. I really like them, though.