Tilt-shift lens to replace wide angle and Lensbaby?

A TS lens generates more new photographic opportunities than almost anything else you could buy. I suggest that you look for a TS24 original version s/h on which to learn. Then if you don't like it or, conversely, want to upgrade, you can sell it for pretty much what it cost you. Although the original TS24 has a bit more lateral CA than is really desirable, it is a pretty good lens in its own right (see the Luminous Landcape 24mm comparison of a few years ago) and perfectly capable of producing some excellent images.

+1 to what Bronze Age Man said.