Mac Pro 1,1 - another what video card question

[crazyeye]

Hello All. This is my first post. I just purchased a Mac Pro 1,1 - 3ghz system on ebay. It comes with 2gig ram and no video card. I need to get a card and add some ram and I've been following the discussions on here regarding this topic. I'm not too much of a gamer. I do some light digital photography, pro tools, watch movies, and would like to be able to use windows in either bootcamp or parallels if need be. I have 2 questions:
As far as ram- I was thinking of adding 4 gig to bring me up to 6. Can I pop a 4 gb chip in next to the 2 that is already there? At what point for my use could I expect diminishing returns regarding ram? Is there much difference between 6 and 8 gig and above? Is there any difference among the various resellers that sell mac pro ram?
As for the video card - it seems that a flashed version of the ATI 4870 is the best way to go. Can I purchase this already flashed on ebay or elsewhere or do I need to do it myself? Sorry for the newbie questions and I apologize if this is in the wrong place.
Thanks.

[Hmac]

Lot's of threads around here on flashing a 4870. That would be a cost-effictive way to get a good video card in there. I have a 1,1 / 3.0 ghz Quad but opted for the Apple 4870 because I need two dual link outputs.

As to memory, my arrangement is as below.

[crazyeye]

Does that mean that if I opt for the PC card I can only use 1 monitor, or am I not understanding that properly?

[Cindori]

two monitors, one dual link one single link

[Hmac]

Does that mean that if I opt for the PC card I can only use 1 monitor, or am I not understanding that properly?
No, you can use two as long as the second one isn't a 30" ACD. AFAIK, both the Apple and Dell 30 inch monitors require dual-link connectivity. Wouldn't be a problem for you unless you're running two 30 inch monitors.

[crazyeye]

Cindori, I noticed on a previous thread that you had a couple of flashed 4870's you were looking to get rid of. Are they still available?

BTW, How do you guys thinks this 2006 Mac Pro, assuming 6 gig ram and the aforementioned 4870 would compare to my PowerMac G5 1.8 single core with 4 gb ram? Should I expect a pretty significant difference or will it be subtle? Just trying to get my expectations in line and figure out a budget for upgrades.

Thanks

[PurpleLogix]

It will blow the G5 out of the water. I love my MP.

[Cindori]

still avail, pm or email penna.ha at gmail dot com