>Any recomendations for a WYSYWIG HTML Editor with Spell Checking capability that can use a Memo Field as a Control Source?

TxControl - it's an ActiveX and can do a variety of formats, including the recent crop of Word. Doesn't have a controlsource property, but you can insert your code to refresh and save the contents at any of the appropriate events, and it has a lot of them exposed. The version which can use stylesheets is a bit more expensive.

See at http://www.textcontrol.com/en_US/products/activex/overview/