The 137 is a semi where the 330 is a full hollow. I have a buddy that had one & I thought the construction was a little sloppy but it had a really nice overall tone. I would probably just go with a 335 personally. Its a proven instrument & they always sound great. The primary difference is the 137 has a single cut & the 335 is double cut. Scale length is the same & I believe they come with 57 classics but am not 100% sure of that. the challenges most people have with a semi is if you play with a lot of gain & volume they can squeal on you. This can be eliminated by standing far enough away from the amp or waxing the pickups but in some cases this can be an issue.
The ES137 Classic comes equipped with 490R/498T pickups, not 57 Classics as you guessed. My 2004 model now has a 57 Classic in the bridge position, which was what Gibson should have done at the factory. IMO the 498T is a lousy pickup that yields no clean tones, only unpleasant distorted ones.