No board supports Phenom X4 9650.
The Acer Boxer 61 board is not compatible with the Phenom x4 9650. The board page you shared doesn’t mention support for that processor model.
It works with Athlon and Sempron chips. The 9650 AM2+ is unlikely to work. Athlon II could be a better option.
It seems the latest Athlon II model is unlikely to keep up... I'd prefer the AM2 Athlon 64 on the K8 platform.
It seems like the 430 chipset is comparable, so a BIOS upgrade for the Athlon II X2 might be feasible. You're likely right about that.