Thinking about upgrading my hobby bitcoin rig and looking for some advice on a motherboard with an LGA775 slot (either an E5300, or a spare Pentium D) that uses DDR2 memory (either 800 or 667) and has at least 2 x16 slots and at least one additional x1 slot so I could expand to another GPU card. My local Microcenter has a great site to search by board specs, but they do not have anything with 2 x16 that still has another x1 slot.
Are you seeking performance or value? Newegg has a board that fits your criteria in the recertified section.