Why pumpkin seeds? they don't get near the size of BG?
here is a link to fishbase.org, this is what they say about pumpkins
http://www.fishbase.org/Summary/SpeciesSummary.cfm?genusname=Lepomis&speciesname=gibbosus

Lakedoc believes that smb spawn better with some current and I have also read of them spawning in rivers. They are really a river fish, being quite populous in the upper missippi. If you have creeks with rocks flowing into your lake I think you should get above average SMB recruitment. You may want to had rocks or gravel. I don't know how many fields you have near by but farmers ussaly collect piles of field stones you may be able to get just for hauling them away.