Yes, having it custom build (well, by the same shop selling me the parts). Looked at some pre-build models (like those sold by Dell), but yes... a lot seem to offer something a little different from what I want and it isn't always that clear what is in such PC's. (Plus, their site has lost most of it's transparency). And I had one bad experience with Dell: my old graphic card burned out and I had to replace it with a new model, but... the power supply JUST supported the stuff in the machine, and new cards used a bit more power. Took a while to order a card that was more energy efficient. So... I prefer to have a little to spare, this time around.
I think I am sticking with the card I selected. In the links handy you posted, it seems to preform better than that card you have and it is only a little bit more expensive. Plus, it got general positive reviews as well. (And it is a bit newer than your card). I just hope there isn't some nasty SL incompatibility issue.
Didn't go all out on the CPU. A matter of balancing that vs the graphics card (and the cost).
Still not quite sure whether to go for 8 or 16 memory. 8 seems to be enough for pretty most everything, but... well... not sure.
Also, still a bit unsure about the motherboard. Hard to tell what is good and what isn't. And how expensive does it have to be to be good enough? May try some comparisons with that link of yours. Thanks for those.