I built a SW Sport Hybrid, and I am asumming it has the same seat.  I also have  a Necky Kayak, and I find the CLC seat and backband more comfortable.  I adjusted the backband to a higher location by running the shock cord throught the bottom loops on the back band.  I have chronic lower back pain, but for me, the CLC seat is better.  Try the stock seat and go from there.

Thanks Dave.  You sound like the perfect guy to answer my question too as I also have lower back trouble sometimes.

I will likely order the kit over the Winter and get set for a June/July build when my wife "The Hot Redhead" and I come back to Maine from Ukraine for our Summer visit with my family.

When we get the place for it in Ukraine I'd like to build a couple yaks there too.

Thanks again.

ive been very happy with the creature comfort seat in my shearwater

I just recently attached the grande hot seat, that CLC sells, to the top of the stock tractor seat. It is slightly more narrow and about an inch and a half longer, but really makes for a comfortable seat overall. It raises my seating position about 1/2 inch which I like. West Marine sells this seat as well. 

I didn't even try the standard seat that comes with the kit-I went straight to an NRS "mild" Hot Seat, with an additional 3/4" layer of minicell foam glued to the bottom. Unfortunately, I still got numb legs after 1 hour in the seat. I just started using a sculpted foam seat I made of 3" minicell, and so far, it is the best seat I've used. You can go to YouTube, and  watch Nick Shade's video on how to make it. Not difficult!

You can get also pre-sculpted minicell seat blanks (or a custom seat) from Redfish kayaks if you don't want to carve your own - I have one in my Shearwater and Wood Duck and they are the best.  I had Joe Greeley (who makes the custom seats) leave the seat back unattached for the Wood Duck seat and I'm putting it at the correct location for my husband's lower back support since Joe usually attaches them low for layback roll possibilities (won't be happening in the Wood Duck any time soon!)  I've never had any numb leg issues and neither has my husband with these seats.