I was looking at these kayaks. Is the h12 the one to get for year-round fishing?( Including cold water winter fishing?) A SOT seems to vulnerable for cold weather fishing.

You would be correct, SOT is a colder  wetter ride. Hybrids protect you from the wind, and because of confined cockpit, you stay warmer. Choice is really about the ability to "self bail", or having scuppers or not, and if due to the type of fishing you're doing you need that ability.  Important note though, when fishing in cold temps, or cold water situations, you NEED to wear appropriate gear, and always wear a PFD, no matter which yak style you choose. Tight lines, good luck, and have fun.

man that h12 is a slick looking unit!  i'd never seen that one before.  

The SOT can be wetter and colder, but i assure you once you get some water on the inside of that sit in, it'll be just as cold, if not colder than the SOT unless you manage to bail all the water out.  the self bailing scupper holes are great, keep all the water out of my SOT.  i have no scupper plugs and have no use for them either.  i used to have a sit in, then bought a sit on top and would never go back to the sit in.  But it's all personal opinion and experience.  

I fish straight through the winter here in Maryland. Water temperatures at their lowest can be in the mid to high 30's. Mostly I deal with water temps in the 40 - 45 degree range.

I wear a full drysuit and have my PFD on 100% of the time. I have practiced deep water re-entry into my sit on top kayak.

In my opinion a sit inside kayak or a hybrid is not a great choice in cold water. If you turtle and swamp either of those you could be in serious trouble. At least with a SOT, if you are able to re-enter your kayak, you stand a better chance of surviving.

A sot provides the ability to stand and fish also. I have a buddy with the 12t and it's plenty stable to stand and fish from all day. 

The H12 is just a copycat of the native ultimate and WS commander kayaks.  I'd look at those two models before getting an Ascend

If you like the H12, take a look at the Jackson Tripper 12. It's the recreational version of the Kilroy fishing kayak. I have one, and for a few bucks I was able to add yak attack rails and now can install just about anything on them. 

I need to take some pics and do a write up on the Tripper 12.