The power consumotion on al lthose cards is pretty low and i'm sure you could run any of them with 430 watt psu.Only question is is what type of PSU it is and what kind of condition it is in.So what is the make and model of your current psu?
Their is no downside to having more power than you need,it would probably be better for your future build and a future corssfire/sli.
It's probably about 2 years old, same model that came with the case, but a newer one case the first one died. Thermaltake XP550NP.
Called the place and talked to a guy who basically agreed with most of it, he said he probably wouldn't totally recommend the 450 with my psu, either way, I'm getting a GTS450 but a new 550w psu. As well as some more RAMbo.
I would reccomend going with the 5670,it would still get bottlenecked but it wuld be capable with running med. settings.The biggest problem you have is the CPU, BFBC2 requires a lot of CPU and GPU performance.If your up to it a 5770 would be a better option and it would be great for a future build as well.Playing that game with 1080p resoution will also put a big strain on the graphics card.