I have the m16 in brass and a Launcher clone. I was going for the Caravela at one time (love sailing and it's pretty) but decided against it. See
Caravela Clone Review from Fasttech-Dat Ship Doe-VapingwithTwisted420 - YouTube
Twisted loves the mod, but notes that the one he has
1. didn't have all the 510 pins that the real Caravela comes with, which meant that some attys didn't sit flush. idk if the one you're bidding on has these, or has an adjustable 510 connection. m16 has a floating connection, so everything sits flush.
2. There's no delrin insulator on the Vela firing button, so the battery ends up sitting on naked metal. That rules out some batteries. Twisted is using a green Panasonic. Your clone might have a delrin; idk.
I'm sure both mods are great, btw. I was just going for a first mod, and wanted things as simple as possible.