GET ONE NOW! I just bought an AMD K-7 700mhz, and a Microstar mobo (awesome mobo) 6pci slots + pc133, ata 66, yada yada... I run all the programs you do, I have Win 2k, and a Voodoo3 2000. I also run Photoshop, Illustrator, Dreamweaver, Flash, Fireworks, Pagemaker, Quark, 3D Studio Max, and a host of other Design/3D software. I also run Everquest (works great), Quake 3, Unreal Tourney, Swat3, Asheron's Call, etc. No probs.
As far as price goes the 700mhz is really the sweet spot. I went to a computer show and purchased the mobo for $140 and the CPU +3fans for $279. Plus a 128 stick of PC 133 ram for $109. Can't beat that upgrade. The 750mhz is $100 dollars more, (not worth it) so my advice is FOR THE LOVE OF GOD DO IT!!!
Just my 2 cents....
Thend