'Coupla thoughts:
- you probably don't need hold downs on the router & saw - the forces on
them are pretty small
- you only need 2 hold downs on the brake - to keep the front from lifting
- you do NOT want to use bolts of any kind - you do not want to be
screwing & unscrewing bolts every time you use it. You want to move it
into place, lock it down with MINIMAL motion & get to using it.

I would do something like this: have a plate in the floor with a keyhole
opening (a circle with a smaller tail). On your brake you have a bolt
whose head fits through the keyhole circle & whose shank fits the tail.
You move the brake over the floor plate, lower the bolt through the
keyhole, slide it slightly into the tail, & tighten the bolt. NOT by
running a nut on its threads, but with a pull toggle clamp, like this:

http://cgi.ebay.com/Toggle-clamp-pus...l_Work_Holding

One flip of the lever tightens you down & another flip releases.

That's how I would do it,
Bob