You can make anything work for warm water but not everything works so well for cold water.
If you're going to do that then you would need to pick a unit that can handle the weighting needs and lift requirements for cold water and put up with the bulk and lugging it along to warm water places, taking up a lot of room in your baggage.
Probably the best option if you are weight conscious for flying is an aluminum plate and wing combo. Aluminum plates are only about 3 lbs lighter than stainless and the extra weight needed in cold water can be easily placed on a belt or cam band. Or just get a stainless plate which is more ideal for cold water and figure to lug it around airports. Many people do that. You would need to start with something like a 30# lift wing and use it for both cold and warm. Then when money allows you could get a small 18# warm water travel wing. The nice thing about plates and wings are everything else like harness, cam bands, plate, stays the same for all diving.
BP/W are very compact compared to overstuffed full featured jackets and back inflate hybrids.