Originally I was just planning on calling him down, BUT.........

[9c] in BB (7 handed)
MP (new - seemed solid) raised, folded to me and I called
[Kd][Kh] Pot 4.5 SB
I check/call
Pot 3.25 BB
I check with the intention of just calling, but then realized that if I check/raised I could
A - represent a King and have an outside chance of gettin him to fold a hand like TT or JJ because the pot is still relatlively small
B - Safely fold if he 3-bets
C - Not let him see a free card with 2 overs, again getting him to fold if he fears he's drawing dead

Obviously I would have preferred a black card, but at least it wasn't another diamond.

Best move against a solid player or fancy play syndrome?

I struggle with this. I am not a big fan of it, but recognize that as you move up in stakes and face better competition this play probably has merit. Against an average player though, you are not getting him to fold 10 or JJ. They will call you down, which isnt bad because you will check behind on river (right?).

If you will fold to a re-raise, or check behind on river then I can live with this play, but i would always have the nagging feeling that I could have seen a showdown for same price if i had not raised turn.

Yup. Fold to a re-raise, check the river.