The Samsung Wave II fulfills all your requirements in that price segment. However, the phone currently runs on Bada v1.2 and although Bada 2.0 demos were shown on the Wave II, there is no official confirmation from Samsung that the Wave II will be updated to Bada 2.0 in the future.
Instead of the Samsung Ace, we would recommend that you go for the Motorola Defy in that price segment. It features a 3.7-inch touch screen display in a rugged form factor and is powered by a 800Mhz processor.
It runs Android operating system with a great music player and superb social network integration. The phone sports a 5MP camera with image stabilization and records videos in VGA resolution.