I think the truly custom boards by Flyboy, Shred Stixx, etc would be a major jump from the boards you are riding now. I would probably look at the Inland Surfer, Phase 5, Shred Stixx (non custom), etc. I have been riding a IS Sweet Spot and just picked up a JWSM and they are completely different in the way they ride. The JWSM makes my Sweet Spot fill like brick, but I have not been able to figure out how to ride it yet (not the boards fault, just my skill limitations).
There are a few IS Sweet Spots for sale on centurion crew right now. And I saw a few Shred Stixx boards on this site.