http://cgi.ebay.com/NOS-ODYSSEY-PITB...QQcmdZViewItem
a buy it now for about 30$ USD.
What are you looking for in clnchers? some nice knobbies? some for racing? some for firetrails? Cause if you are just putting together a fixie for 250-300 then stick with something cheaper like ritchey speedmax pros, they sell for about 10$ a tire and can go up to a 35c (so far as I've seen) and they are decent for firetrails with low mud and nice for cornering on city pavement. Thats my opinion tho.
you might wanna msg TIMO or 92degrees, both have given me great setup tips along with everyone else on the site.
I never seen the pitbulls before but what makes them interesting is that you can supposedly mount them just above the bb on the wishbone. would be different to see, but I wouldn't know what it would be like for taking a beating that low on the frame...