The Tech Boots that come standard with the Guardian, they're attached. I also use Fourth Element's arctic socks. Which BTW are awesome.
While the standard Tech Boots look good I might want something a bit more robust, possibly go the rock boot route again but possibly go up a boot size. Puget Sound beach dives can be pretty rough and I have a lot to carry.
Interesting review on the suit. In the comments the reviewer answered a question about warmth and replied he felt even though it is neoprene, it is crushed to the point it doesn't feel any warmer than a trilam to him.
Thanks.