I use Newegg Business and Amazon.com for these type of purchases. Read the reviews on those sites should help you make a decision. A quick search on Newegg for "DVI KVM" shows dozens of models available, you can sort by rating.
Also, when you're ready to join the big boys, this is the KVM I use for my server racks. Def. recommend.
http://www.amazon.com/gp/product/B007WLRF6M/ref=wms_ohs_product?ie=UTF8&psc=1
