Alright, so this is my idea, it's quite simple, but it could be very cool. Bring Hey0's server mod for SP. All of the commands (not the ban and kick of course), and being able to install hey0's plugins for SP as well. Although this would be quite hard I think it would pay off. And with help from Hey0 one might be able to just convert it to work with SP. So please, tell me what you think.
Why not take the easier, less tedious route and set up a personal server that only you can access? You can have all the awesomeness of smp mods without breaking them trying to make them work for ssp and having to re-unbreak them everytime Notch puts out a new update.