My 9800 Pro performs well enough on my current system...so I'd expect at least that, but also an improvement with either of those cards I mentioned on my new system as everything is larger and faster (256 MB on the video card coupled with the faster processor, L2 1MB Cache, PCIExpress Slot, DDR2 Memory, larger FSB)....should be a great improvement? Also looking forward to the Intel's stability...
Yes, definite improvement. And yes, intel's are highly stable. However, make sure to have a good PSU. Intel CPU's begin to wavers as the power they get decreases even by the smallest bit.
Anyhow, ideal set up would be to build this P4 with one of those OpenGL cards, and then upgrade my AMD system for gaming......just what I need....more money to spend on computers

Yep, thats what i do. Two AMD's for gaming and the rest of comps are all intels.
Please do recommend the OpenGL cards, and approximate price if you know it....Thanks!
Sure. And just so you know, the technical term of these cards is workstation-class cards.
ATI cards (FireGL):
ATI cards are lower-end cards. They're the cheapest of the lot. They're good as beginner cards. They have most of the functions nessasary for high-end gfx like Avid or XSI. However, due to their rather powerless GPU's, they have extremely long render times. this is ok for the "average" (many digital artists use these cards for their own home use) user but for business, is generally unacceptable.
Word of Caution: AGP FireGL cards are a bit aged, so go with the PCI-e cards. If you have the money for a workstation class card, a PCI-e mobo should be within your price range.
ATi cards are very cheap with their flagship model selling about about 800 bucks.
http://www.newegg.com/app/viewProductDesc.asp?description=14-102-468&depa=1Nvidia Cards (Quattro):
Nvidia sells two variations of this model. The NVS and the FX. The NVS is a 2d card. I have found no use for it whatsoever when i bought it; I didn't lose any money, these cards are cheap at around 200 bucks.
The FX is a mainstream 3d workstation card. It has all the features you'll need. This is a extremely good card confirmed by benchmarks and by my own testing and animation projects. It however is not cheap.
A list of FX cards can be found here:
http://www.nvidia.com/page/quadrofx_family.htmlThere are too many to list, but I would aviod anythign below a fx1100.
I have personally used the fx3400 and i can't complain. Awesome gfx power. Its sheer processing power can even be compared to the latest intel prescotts. It actually has more transisters than an intel p4 540.
The fx4400 isn't out yet, so i can't tell you much about it except it will kick ass and then some. Keep in mind also that SLI is supported (or will be). So you can have two of these later on.
Even a simulation of an incompressible fluid in CAD works fine (though such simulations are CPU-intensive, gfx power is still a major factor).
However, again, performence comes at a price.
This is the currently best fx card (until the 4400 comes out) and it'll set you back by about 1500 USD.
http://www.newegg.com/app/viewProductDesc.asp?description=14-133-121&depa=13dlabs (Realizm):
The Overlord. Once I switched to these cards, I couldn't go back. I personally bought a Realizm 800, the flagship (and the only PCI-e) card of 3dlabs. This card puts my oldest computer to shame ( a 3.06 ghz intel w/1gig RAM).
This card is card is gfx gold...no...diamond. The love I have for it cannot be expressed in words.
However, its comes at a steep price.
About 2,300 for the realizm 800.
http://www.pricegrabber.com/search_getprod.php/masterid=6199881I actually bought it for slightly more.
Even 3dlab's lower-end product (which is AGP btw) is excelent, but still exspensive, about 560:
http://www.newegg.com/app/ViewProductDesc.asp?description=14-124-113&depa=1Well, there you go. Hope this helps you out.