Well, your request is one I have never seen. Although I am not about to pop a case open to measure, here are a few overall dimmensions. My Radeon 9800 Pro was about the identical to the 9500 Pro I think.
Only took a few minutes as they were in the boxes not in systems, and I ran a few benchmarks while measuring. Subtract about 1/4 each way once it's in the slot and case. There are also lower profile half height ones too. But I don't have any in stock now. I know GF2MX's were often that way, as well as a radeon 7000, and many newer cards too. But they are probably all too slow for games and usually have passive heatsinks.
Radeon 9500 Pro 7.25" x 4.25"
Radeon 8500 LE 7.125" x 4.25"
Radeon 32MB DDR (7200) 6.875" x 4.125"
MSI GF4 Ti4600 8.75" x 4.25"
MSI GF4 Ti4400 8.75" x 4.25"
MSI GF4 Ti4200 7.25" x 4.25"
ABIT GF4 Ti4200 7.75" x 4.25"
Gainward GF3Ti200 7.625" x 3.625"
Chaintech FX5200 7.00" x 4.25"
MSI GF2 Ti 7.25" x 4.25"
PNY GF2 Ti 6.5" x 3.75"
Matrox Mystique 2MB PCI 6.00" x 3.5"
ABIT IS7, P4 2.6C, 512MB Corsair TwinX PC3200LL, Radeon 9800 Pro, Santa Cruz, TruePower 430watt