780G and Athlon II X4 640 for playing GC?

[Metromon]

Hello,

I want to buy a new processor to play some GC Games on my computer, because my Gamecube have been damaged.
Currently I own these games:
Metroid Prime
Metroid Prime 2
Pokemon Colloseum
Pokemon XD: Gale of darkness
and some others, but those above are the most important for me (first two are my favourite, while second two are favourite for my younger cousin [and to be honest, one of my other favourites])

My specs:
- ASUS M4A78-EM (Radeon HD3200, DDR2)
- 3 GB RAM [1GB noname 800MHz CL5 + 2GB G.SKILL 800 MHz CL4] DDR2
- no external video Card (i'm only occasionally plays and energy-efficient is very important for me, integrated video card is working well for me, because even if i play, i play for older games, like c&c 3). If it is possible, i prefer not to buy external video card (as i read, most important for dolphin is processor)
- 256 MB Shared memory for integrated video
- AM2+ Socket

I want to buy AMD Athlon II X4 640, which i think is the best processor with TDP 95W or less compatible with my processor (as well as it's really cheap). Or maybe i should consider other processor compatible with my motherboard?

I will not change my mainboard at least until July.

Also, i have a question about Wii Games - does they require much faster cpu/gpu than GC games (i mean Metroid series: Other M, Prime 3)

Thanks in advance and sorry for my English

Ah i almost forgot: I want to play games i wrote (i mean GC Games, not Wii). I don't need high resolutions and don't need any graphical-improvements. just want these games to be PLAYABLE.

[DefenderX]

All games you mentioned are VERY demanding, especially Pokemon XD and Pokemon Colosseum. The AMD Athlon won't handle this games, sorry.

[NaturalViolence]

The IGP is a bigger concern. Without a graphics card you simply won't be able to get tolerable framerates on that system.