Does chipset matter in HTPC if using discrete video?

So I understand that chipset matters if you're going to use onboard video but if I'm going to use a discrete card (say a Radeon HD4350, which by all accounts is much better than any onboard video) does it matter which chipset I use? In other words are there any real differences between say 780G/785G/790G? I plan to use a Athlon II 240 chip.

An alternative is a cheap intel board, probably G31 or similar, and a Celeron e3300.

Any thoughts on audio capability of any of the chipsets mentioned?