I've been through many off the rack wetsuits and even dove dry for a while but now am back in a custom wetsuit.
I think a custom wetsuit is the ultimate solution.
I got one made from a place called M&B wetsuits in Long Beach, Ca. The suit I got is a bit much for even the North Coast unless you're a commercial urchin diver. It's 1/2" thick (13mm) made out of Rubatex G-231 neoprene, which was USA made and is no longer available. I could dive in the low 40's or even the high 30's in this suit if I wanted. The only reason I got this suit was because it was the last of that type of material available forever and I wanted to be part of history, plus you never know, I may start urchin diving some day.
The cut of the suit is a top and bottom farmer john style old school beaver tail with stainless clasps, attached hood, 3/4 zip up the front, with kevlar on the elbows and knees. The general cut patterns for this suit are the same ones that the company used back in the 60's and haven't changed. This is about the best combo I've found for a wetsuit. The attached hood makes a huge difference to prevent leakage. Another feature that helps with warmth is to get a suit that has a slick smooth skin on the inside. This removes a layer of nylon inside the suit that can hold cold water and gets the gas cells in the neoprene closer to your skin making heat retention more efficient.
Those one peice suits with the attached hoods that so many people use have that annoying zipper across the chest that I never liked.
In Fact, most high quality freediving suits are modelled after the beaver tail suits for good reason; because they are the warmest combo developed so far with the least amount of neoprene.
Almost all off the rack suits I've seen lately are being made out of the super stretchy soft stuff that feels great in the store and is widely used because almost any body type can be compensated for, but if part of the suit is overstretched to compensate for a large area on a person that also means that the material is thinned out in that one area reducing the thickness and effectiveness of the thermal layer. Not only that, most of the super soft stretchy stuff flattens out to nothing within a few atmospheres of pressure rendering it useless when you need it most. This is why I say to go with a custom wetsuit that is made for your exact measurements, plus the fact that you can get it made out of really high grade commercial quality material that will withstand the rigors of compression and wear & tear.
I have another M&B on order with the exact same cut as the last one but made out of straight 7mm this time. This should be perfect.