Very nice recording and compositions!
When I got my Corvette fretless I treated myself to a set of Thomastik Infeld flatwounds. They are indeed expensive but I think pretty outstanding - versatile in tone, allow a good deal of expressiveness and (it says it on the package and it's true) "supple feel".
Also, I have LaBella tape wounds on a Peavey fretted and they're surprisingly lively strings and more versatile than you might expect. The A and E do put out a lot of low end but you can dial that down with technique and EQ.
A friend uses half-wounds which might be a nice middle of the road solution.
Here's a sample of the Thomastiks on the Corvette: https://soundcloud.com/yawnotec/birdsong-remix-2