stabilizer pole lower brackets are largely in compression. you'd be surprised how much load a relatively small bracket will hold in that load configuration. a bigger concern would be the load on the mounting surface, and the pivot point. the custom fabbed units are probably the best option as you can design them to fit the application. i'd also use a reasonable sized bronze bushing in the pivot area so there's no egging out the bracket or pole. the hydraulic cylinder mounts are a good idea if they fit the area, but some don't have bushings in them so choose carefully. the mast and rigging needs to be pretty skookum as those loads can be high and there can be a fair amount of cyclic loading or shock loads depending on what hardware you have in the water.
i've been contemplating what it would take to rig up stabilizers on my boat too, my wife would appreciate them. in reality though, for the protected water we typically run in a flopper stopper for use at anchor will probably be what i do.