gearspy:
Welcome to AVS Forum!
DVI cables from Lindy and Pacific Cable are quite reasonably priced, so that should not deter you. As for picture quality, it depends on the type of display you have. Go look at the (October, I think) issue of Widescreen Review where they review the Bravo D1. In that review, they discuss the relative merits of DVI for various display technologies. In essence, fixed pixel displays (e.g., DLP LCD, plasma) benefit the most while CRT-based displays benefit the least.
As for DVI switches (you don't want a splitter - that is for sending the output of a DVD player to two displays), the Gefen switch works but there have been reports of interference between the Gefen remote control codes and other components. Supposedly Gefen is working on this... There is a DVI switch that Lindy is offering that is due to begin shipping in February for a reasonable price (I have a link in my report on DVI switches in the RPTV forum - do a search and you should find it). The only drawback with this switch is that it doesn't have a remote control although they are reportedly working on a model that will have remote control capability.
I have a DLP display and I can tell you that the difference between component DVD and DVI DVD is quite remarkable. I also have a DVI-output digital cable STB and the improvement there is also significant over component connections. It's worth your time to investigate this issue further, again, depending on what kind of display technology you are using.