Need some help with a video card...

[FordFan86]

Time for an upgrade... my Radeon 9200 just don't cut it no more (gaming)..
My main question is for you techies out there, I'll leave brand names out of this to get a better answer.
I basically want to know the difference between all the bits and pieces of information thrown at me, the prices of the cards are within $20 of each other.. I'm unsure which is "better", though i'm slowly building a picture out of the masses of reviews, tech boards and wikipedia articles I read.
Here's the specs I am trying to compare...
#1
256MB 128-bit DDR3, 560MHz Core Clock, 1400MHz Memory Clock.

and I'm trying to compare this to
#2
512MB 128-bit DDR2, 625MHz Core Clock, 800MHz Memory Clock.

I read somewhere that DDR2 will clock twice as fast as DDR, as well as running on less power and managing heat better... so by my thinking the DDR3 @ 1400MHz is effectively the same as DDR 2 @ 700Mhz (in which case card #2 wins at DDR 2 800Mhz, aswell as being 512MB).. Or am I way off?
Both cards seem to have the same/very similar pixel pipelines, shading capablities and filtering rates etc. however #2 looks like it has a better cooling system. From what I can see both cards have been taken from their original manufacturer and tweaked slightly. They are both built around the same time and are in the same section of marketing.

After a few replies i'll post up the link to each card.. unless some die hard fanatic out there knows which ones i'm talking about already and can tell me which is the better of the two.. or that the difference is so small you can't tell...