Rafal, you can get some awesome pit colors without going to morphs.
Take a look at pituophis lineaticollis. Awesome light greenish yellow with leopard spots. Get big, have huge clutches and are bulletproof. My big male is pushing 7 feet and is stunning.
However if you go the morph route:
If you check out Jonel Lopez's site - Selective Propagations - you can see some killer morphs that he's produces. IMHO, Jonel produces some of the nicest pits (and takes some awesome pics to boot).
http://www.spsnakes.com/snakes.htm
Jason Nelson of Envy Reptiles specializes in gopher and bull morphs and has a seemingly infinite variety.
http://www.envyreptiles.com/
Then there is John Cherry who specializes in locality pits and morphs. John will gladly talk to you all day about them.
http://www.cherryvillereptiles.com/
All three of these guys are top notch guys who produce top notch animals. Browse the sites, check out the morph and see what grabs you.
I currently have some red phase northern pines, the linis, a couple locality deserticola, some kingsville reds, some dwarf colorado locality bulls, black pines, deppei jani and my favorites - ruthveni (louisiana). If you'd like some pics of any of them, shoot me a PM.