I got a pair of Swalbe Marathon Racer 26x1.5 tires for a really good deal from http://www.davesbicyclerepair.com/ for a great price, $30 each. Those tires cost more than the rest of the bike! It rides great with those tires.
I wanted a rack on the back, but it would have to be an expensive adjustable rack to fit. Those cost about $60. I got a piece of 1/4" aluminum bar stock and some 1/16" thick aluminum angles at Home Depot for $7. I had a couple of pieces of 1/8" angle in my scrap bin. That and some stainless screws and flat black paint was all it took.