the halo rims are plenty sturdy (albeit a little heavier than trials ones) but you'll find the rear hub won't have a reliable enough freehub, you need (or will quickly find yourself needing) a hope pro2, a king, or a screw on type hub that you can fit a trials freewheel too. or you will struggle with 'pure' trials moves. trials frames aren't really like other bike disciplines where you have a certain size to fit a rider, you just pick a stem that reflects your height, i'm 6ft, i ride a 20", but i've spent enough time on 24s and 26s too. so don't feel your size should affect your choice.
the fourplays are brilliant frames, they're made very well and the geo is awesome. i will say i think it's much harder to learn trials on a streety bike, and that it's easier to learn on a seatless 'pure' trials bike, with geometry that compliments trials moves. what sort of riding are you wanting to be doing?
as far as brakes go, good cable brakes (avid bb7) are just as good as the premium hydraulics(shimano saints and hope mono trials) Vee brakes can be very good if you take the time setting them up and run some of the premium pads that are available.