I purchased a razor with a concave blade and it works great on your neck. You don't need a drastic curve to get a really smooth shave. I picked up a sheffield razor on Ebay and after the proper honing, it shaves like a dream.
"If you want it, that's what you do best" - Woz
"if you ain't bleedin', you ain't learnin'" -me
remember all, each thanks given will ... (virtual ego +1)