I was looking seriously at Seaskin recently. There wasn't much about them here on SB, but it seemed to be all good. Then I went on a UK diver's forum (thediveforum.com) and found a lot more posts about them. The sentiment there seemed to be that Seaskin used to be great, but in the last year or two, their quality has become somewhat questionable. I don't know, myself. I'd just say that if you are considering Seaskin, go on that other site for a bigger base of knowledge.
I have a crushed neoprene suit and a "shell suit". I had shied away from a shell suit before because the less snug fit made me think it would be much harder to manage the air bubble inside. What I have now found is that the shell suit seems to compress around my body to be even more form-fitting when I get in the water, as compared to my crushed neoprene suit. The result seems to be that it is actually easier to dive in. I.e. in the shell suit, I feel like I have less air just running around inside trying to upset my trim. And the shell suit is way more comfortable to be wearing the surface. It's lighter. Mine is breathable. And it doesn't make me sweat my butt of anywhere near like the crushed neo does. OTOH, the crushed neo is so tough it's like it's nearly indestructible. OTOH, my 4th dive in my shell suit I was taking pictures during a wreck swimthrough and bumped my legs on something that was sticking up from the bottom and I got a small hole cut into the thigh of my suit. I got out very wet. Not a total flood or anything. Just pretty well soaking wet, mainly from the waist down. When I eventually found the hole, I dried off the inside of the suit and put some Gorilla tape over it and that allowed me to continue diving with no more water coming in. Then some Aquaseal and a piece of drysuit material and I patched it good as new.
I have not seen one in person, but the things I have read here on SB make me feel like the top suit I would look into if I were buying a new suit would be the USIA Techniflex. It's a stretch tri-lam. And you can get one custom sized to your measurements for something like half the price of a Santi or DUI. And they are made in the USA. Dive Right In Scuba is a major dealer for USIA and also has awesome custom service, so I would talk to them about one.
I would definitely make sure whatever I got has thigh pockets. My first drysuit does not have thigh pockets. My newer one does. I am SO glad for the addition.
I have not used a DUI suit or zip seals. What I've seen/read/heard makes me think that when you use dry gloves that attach with the zip seals, you have to attach the gloves to the suit before you put the suit on. If that's really how it is, I would not like that at all. I like to put my dry gloves on pretty much last when I'm gearing up. I've tried it a few times where I put my dry gloves on as soon as I don the top part of my dry suit and it sucks.
Latex seals are actually pretty durable and most off-the-rack suits come with them. They are definitely durable enough that you should not feel like you have to start right off with a suit with changeable seals. If you find a suit that fits well, for a good price, and it has glued-on latex seals, don't let that sole fact put you off of buying it. You can always get it changed to use replaceable seals later. As long as you take pretty basic care of them, stock latex seals will last a long time.