Glad to see you went with the WRSI and the Astral.
I'd definitely get a jacket with latex gaskets (some come with neoprene & a latex rim). That will give you the best seal even though they're not as comfortable and take a little longer to get used to.
Immersion Research (IR) is a great company with great products.
The X-Jacket is amazing but the Comp LX is also really good and will save you about $100:
Men’s Paddle Jackets
I have friends in the Kokatat Rogue and are happy with it and I've heard good things about it on the buzz. I've been told to go Gore-Tex with the Rogue. It's a little more expensive.(About $400)
Overall, CKS is the simplest option for purchase. Sometimes you can get lucky when outdoorplay.com gets rid of stuff on sale and occasionally sites like campmor will have a sweet deal but it's rare. CKS will sell last years drytops (at the beginning of our '09 season) for cheaper.
IR also has a closeouts page that's always changing on their site. It's worth an occasional look:
Immersion Research Closeouts — IR closeouts, overstocked items and blems