Normally, I would recommend 5mm (unless you particularly feel the cold - perhaps coming from the tropics) open-cell suit (against your skin, not a rash vest) with spearo trousers (high waist) & nylon outer (such as made-to-measure Elios basic Ecoline suit -- there is a Greek company which is cheaper now though).
But, for you pod, as a kayaker, I would suggest that you get a 5mm suit with long-john style trousers - that will give you the option to paddle without your jacket on. Also, with the jacket on, your body core will have 2 layers of 5mm neoprene over, which should be more than enough (provided you buy a proper, well fitting spearo wet suit, with hood).
I think a nylon outer makes sense - it provides a lot of much need protection & strength for the open cell neoprene. However, if kayaking, a smooth outer would dry more quickly -- but it will be much more vulnerable to damage(e.g. from rocks & other sticky out bits), so if you go for that option you might want to consider some reinforcement (e.g. partial nylon outer and/or knee/elbow pads).
I would normally suggest simple, cheap, effective open-cell inside - however, if you anticipate putting your jacket on and taking it off while on your kayak, it might be worth considering one of the fancy slippery interior coatings - which I would normally avoid. You might also want to consider one or more zips - which are not normal on spearo wetsuits but which might make sense on a kayak (I recall the late, great Old Man Dave got zips on his last wetsuit just to make it easier to get on & off - pragmatic).
Neoprene booties & gloves complete the outfit. 2mm stretch neoprene gloves are ok for the summer but I find my 2mm stretch Beuchat gloves a bit cold sometimes compared to my slightly thicker, earlier Beuchat gloves (which are excellent) - but the stretch is a handy feature. I suggest that you choose the thickness of your booties to get a good, slightly loose fit with your fins - rather than worrying about warmth. My reasoning is as follows: if your socks are too thick your fins will be tight & circulation to your feet will be compromised - this will make your feet cold, despite the insulation. In the summer, I sometimes forgo booties as my feet swell with the warmth - but as it is warm, I don't need the booties anyway.
BTW it is possible to be too hot in a wetsuit (which is another reason, perhaps, not to get a 7mm wetsuit). When I first dived in my brand new 5mm Elios wetsuit in November I almost got heat stroke. The suits v. gradually loose a little "loft" (insulation) over time & you learn a few tricks to tweak your temperature -- drink plenty of water the day before diving too, you want to be well hydrated.
A 7mm suit will require that you carry more lead on your weight belt (similarly a long john wetsuit will likely need a little more lead than a suit with spearo trousers).
If you get a suit made to your measurements (a good idea, especially if you normally have trouble finding your size(s) "off the peg"), then:
1. make sure you allow plenty of space around your throat - to avoid choking reflex.
2. take each measurement several times, carefully and as instructed, on both sides of your body, ideally on different days under different conditions (discard outliers, average the rest).