good that u cud get to try out the 2600+ b4 u cud buy it. Anyways, that set-up of urs is not all that bad, if u ask me. U cud wait a little longer, may be for another 5-6 months. That way you cud even go for a complete overhaul, with Prescott being released and the second revision of the current Canterwood mobos released.
Meanwhile, if u do want some good performance, then u cud get a 1700+ t-bred B and then overclock the hell out of it. U cud unlock the multiplier and then may be get some good speeds.
By the way, 2600+ has all the higher mutiplers unlocked right? Can u change the multiplier in the BIOS? If so and if u still have that 2600+, try upping the multiplier adn retaining the FSB near to 140.
<b>still</b> thinking of a good sig. till then...