For my cold water local diving, I have a Halcyon Eclipse 30 BP/W.
Several years ago, I bought a
OMS brand AL BP (approx. 2 lbs.) that was on sale for about $45. I combined hardware odds & ends in my dive locker with some 2-inch webbing for the harness. Since the Eclipse wing doesn't have camband slots, I also had to buy an STA. For about $40, I went with the
lightweight (0.6 lb.) one-piece SS STA made by Oxycheq. These items appear to cost significantly more now.
The 30 lbs. lift Eclipse wing is way more than I need for warm water diving, but the setup works great (not too floppy). To carry additional lead, I have XS Scuba weight pockets mounted on the tank (pockets + cambands cannibalized from my cold water setup). It takes about 5 minutes to switch the cambands out before and after the trip. Not a big deal really.
My girlfriend uses the DSS BP/W system for both cold and warm water diving. Originally she bought a SS BP/W LCD 30 for our local diving. A year later, she bought a Kydex plate that works beautifully with the same wing for warm water trips. It breaks down quite nicely for travel. I believe her setup is about a 1-1.5 lbs. lighter (dry carry weight) than mine. She spent a little more on warm water "conversion" than I did.
We check our BP/Ws, fins, and exposure suits when we travel for warm water diving, and we prefer to carry-on our regs and UW camera equipment.