This question would obviously be best answered by someone who has modded both units.
I would like to point out that the KT-7500 might be a better choice as a modding candidate because it has 5 FM tuner gangs (rather than 4 gangs found in the TU-717 or the KT-7300).
They're both obviously going to sound good. I think it'll be personal preference. But that Kenwood's tuning knob won't be as silky as the Sansui's. Simply said, that's how a tuning knob is supposed to feel.
Thanks for the input guys. I think what I should do is pick up a KT7500 or 7300 and mod it. Fortunately they are still cheap over at ebay.
Since neither of these tuners has remote controls and I only listen to two stations on the radio I guess I could convince the WAF that having one tuner dedicated to each station is the best way to go. We were on something of an "Anti-Audio" disturbance not long ago in my neck of the woods (if you know what I mean).