Well first off I'd like to say I know and respect the people behind Custom Inflatables, I am just a fan of their boats.
Attila dropped off some demos for the summer a few years ago. We had a few seekers and kats, one and two man versions. The kats are really really stable. The seating and foot brace design is comfortable and since your not sitting on an inflatable, it's not squishey/hard on the back. Because they're custom it'll fit perfect and there'll be alots of outfitting options. Depending on use/trip length, larger tubes are a good option.
Ultimately call um up, they prototype a lot and have lots of cool ideas.
My wife spoke with Attila in January and he is building her custom IK for this season. She has tried a bunch of IK's but none had everything she was looking for. He spent over two hours on the phone and many emails went back and forth before she was comfortable buying without trying but he shared his many years of experience. She wanted a boat that mimicked her current boat dimensionally but had more rocker for bigger waves. He convinced her to go for a longer boat to maintain the same waterline and increase the rocker. She definitely wanted an smaller, more responsive boat but went with his recommendation. She won't get it until late May but hoping it will be the "perfect" IK for her.
When she got off the phone, I was ready to order a Thrillkat.
I've only heard good things and look forward to trying it myself.