I think that would end up just being the "FET847" project, as mentioned before.And the last thought of the day... Couldn't you build a more "u89-inspired" mic by not installing the de-emphasis and using Arienne's flat 47 capsule?
I know it's a different capsule, but her flat 47 is just so nice sounding on its own. And those smaller 87-style bodies on Ali are about u89 size.
As for the SMD version - sure, why not? But I guess the better question is why? The whole point of this was an easy-to-make 87-style mic using parts you might already have laying around.
An SMD U87 circuit has been done by AKG (and lots of other manufacturers) for years. They didn't always do it 100% faithfully....but there are only so many ways to skin a cat. Once you start bringing a pcb and surface mount components into the picture, you're better off just doing the Perception 220 to U87 mod.