"Did S&W ever sell a ported 640?
or a ported J frame??? "
Porting is the best thing since sliced bread, as far as I'm concerned. My 637 PowerPort with Presentation Pachs and Hornady CD +P ammo does not have a lot of flash in low light, it does not spit or blow gas at anyone or sound louder or have any other ill effects such as noticeably reduced velocity you often hear about. It has quickly become my all time favorite carry revolver (light, good DA trigger and very controllable for fast, accurate follow up shots), and I've been shooting for over half a century.
Many years ago I rifle-ported my 9" Ruger Super Red Hawk .44 Mag and turned it into a ***** cat. My ported Model 60 .357 was the second best carry gun I've ever owned.
That said, the only time porting failed to significantly soften felt recoil was with the absurdly hard recoiling 329, but, in fairness, I should have tried quadra porting rather than just the normal dual porting.