My nephew used the 2-part and has been happy with it. A little harder than straight out of the bucket but his has held up very good and he does some heavy stuff.
On the other hand I cheaped out and bought the stuff you can use straight out of the bucket. Its held up pretty good for the past 10 years but the bay I use the most needs a recoat!
...jay, I vote two part. Do it before ANYTHING goes in or on the concrete. There may be a wait time but I washed my down with Muriatic acid to etch it some and doing it before walls and stuff go up would make it a lot easier.
...but I know you'll research and do your usual good job. What ever you use, read the instructions first. LOL