Sapphire ATI 6950 2GB GFX card too much for PSU?

My nVidea 7900GT graphics card (full system spec in my sig) is starting to struggle with it being DX9 and all so I'm looking for an upgrade but I'm not sure what to get.

I got a Dell U2311H monitor, so an average sized 1080p monitor.

My budget is about 200 euro so I was looking at the 6950 2GB but I'm not sure if it's too powerful for my needs (some gaming like STALKER: Call of Pripyat but mainly photoshop and movies).

It's also a little above my budget but I think it's worth spending the extra for the 2GB version for the chance to unlock it to a 6970 if it's not overly powerful.

Concern is whether or not my 450W Corsair PSU can handle such a modern graphics card. Is the card too big for my PSU? If so, what card would you recommend?

Not needing to upgrade for a few years would definitely be a prerequisite!

Thanks in advance!

What's better, getting a lower spec graphics card or upgrading the PSU as well as the card?

Cause if there's potential in the 6950 that I won't be fully utilizing, I'd rather get a lower spec one and upgrade the whole system 3 or 4 years down the line.

Not too keen on the idea of upgrading both due to cost. Or is 450W just too small these days?

unlocking is not a must nor is staying with ATI.

I know it's not exactly what I wanted but I would prefer to get a lower spec card that I can use the full potential of (i.e. I don't need maximum quality on a 50" plasma with 60fps or something extreme like that. Medium to good quality with comfortably playable fps is more than enough) and then upgrade the whole lot a few years on.

So the 6850 my best bet?

done some review reading and think the 6850 is my best bet. The current 6850 prices are acceptable enough that I won't be too disappointed if the 78xx's are better or create a price drop. Guess I'll go for that and upgrade my system in 3 or 4 years.

We'll see if AMD actually manage to get the desired performance out of their bulldozer architecture by then otherwise the Sandybridge or the equivalent architecture by then will be the next upgrade.

true, it was a risky move sharing components between the cores but it worked with their APU idea. In theory, it allows them to put in more of their "cores" on a single die doesn't it? I think the potential is there, they just cheaped out a little bit. Some tweaking in later revisions and who knows, they might actually get it working as desired.

Currently their price and wattage is unbeatable though!