To the question weather it's warm enough, you have to consider more variables.
Things like in water time, body fat, being rested, having some food a few hours before the dive, body type, suit material, suit fit, the amount of swimming, the type of use (competition, rec, etc.).
Like stated for the pool you could consider static training and dynamic training, and the pool temperature.
Let me just share with you what I use and what variables I considered.
In the pool I train the water is relativly warm 28c and 29/30c for the static pool.
In both I wear a 3mm high density high waist nylon inside,smoothskin outsite pants. And a 3mm sleeveless vest, made of soft neoprene, metal coating inside, very stretchy nylon outside. This setup keeps me warm in this static pool, and warm enough for my dnf training. Doing 16x50's. It's not very streamlined, but the 3mm keep my legs horizontal. The shirt keeps me warm too, and I love the freedom of movement the sleeveles shirt provides, though I do have enough water ingress when I push off the wall or swim with my monofin. Actually for monofinning I take the shirt off and add a 500gr to my 1Kg weightbelt, because of the drag with monofinning and heat generated.
For competition, I like to use a warmer 5mm suit, because as a preparation I like to lay on the surface for 15minutes and 'sleep' in the water. in 26c water I get cold in a 3mm, especially when I did not eat. Like experienced at Nordic Deep.
For DNF I use a triathlon suit with various thicnkness, ranging from 5 to 1,5mm on the shoulders. I like to switch to a sleeveless design.
For DYN I use a swimsuit.
For depth I use various setups's in the northern European waters, Dutch lakes, German lakes, Swedish Fjord. For training I like to use 5mm smoothskin/opencell, For competition I use the thinnest stuff I can get away with. To me that means being relaxed in the water for about 6-7 minutes within controllable shivering range. For instance in Germany I used my triathlon suit with an old 3mm -sleeves cut off -top underneath. No gloves or booties in 18c surface water, - 2-4c @ 50m depth. At Nordic deep I used my 3mm high density Elios smooth/nylon. You should know that I don't do any in water warm-up for competitions.
Oh about my body, skinny type, low fat, 187cm tall, long limbs, currently weighting 74Kg. It used to be 68-69. And yes than I needed more suit or internal combustion.
I have no experience with other tailor suit manufacturers than Elios. But I intend to have my next suit being designed by them.
Success finding the right suit for your needs.
Kars