The better choice would be an radeon 9000 pro 128mb(it's from Hercules) because doom3 will use 80mb of texture.
If you have the money get a gf4 ti 4200.
DVS radeon 9000 pro has 4 pipelines but I think its a 4x1 config like radeon9700's 8x1.
The benchmarks I've seen on radeon 9000 pro have puzzled me.On test on anandtech shows radeon 9000 pro slower than radeon 8500 in UT2003 and another at digitlife I think showed it faster!!There in no doupt than radeon 9000 pro is better than gf3 ti200,all tests show it is.
My best suggestion b5fan is read a few tests like anands ,toms,techreports and make up your own mind!!