Your not going to find a stock replacement, any 2 spool open center valve will work for you 4 to 8gpm would be fine, You also don't need anything fancy like Power Beyond.
EBay or surplus center are good bets also baileys.
Here are a couple examples: http://www.ebay.com/itm/Prince-Manu...ic_Hydraulic_Valves_Parts&hash=item540126dab6