Thanks for all the great input!
Twings - I've decided to go "the full monty" and just ordered Harken turning blocks, cam cleat/fair leads, and Holt Allen snatches from APS.
Spin Sheets - I'll be keeping my non-ratcheting blocks.
Spin Sheet Cleats - I didn't realize the cabin-top horn cleats were for the spin sheets; I've been using them to lock down the halyards. Seems like some cams would be a lot better if they were in the right place.
Downhaul - I think I will keep mine in the stock location.
Thanks again for the help, if anyone knows of a smart place to put some cams for the spin sheets let me know!
-dan