Everyone will tell you dry suit because that's all they know and that's what's available. I personally use a custom electronic heated wet suit 160 watts but only one exists and it's not for sale, but you can try my backup system which I used many times. The chemical heater.
Make a custom neoprene pouch 4mm, 12 inch by 10 inches., fill it with snap chemical heat packs (6-9 lbs), then stuff it in your wetsuit on your chest, 10 minutes before you dive. Its a lot cheaper and easier than a dry suit and will work
one more tip get a modern 7mm wet suit with watertight wrist and ankle seals, like a Henderson aqua lock, Bare or Waterproof brand
there is one company that makes this Mangrove thermo heated vest dch-v from aditech-usa.com. If you don't want to make one yourself.
1. Premium and most expensive--Custom electronic wetsuit $6000+
2. Dry suit with heater $4000-$5000
3. Dry suit no heater $2000-$3000
4. New wetsuit plus thermo chemical $1000
5. homemade heat pack $200
there are many options depending on your budget.