54 will be small. 58 would probably be closer to his size even with legs that short. sizing is very tricky, the trickiest part of buying a bike for someone else by far. with short legs, you can just lower the seatpost. you don't want your torso to be too long for your top tube.

i'd suggest for someone that tall you stay at 56 or above, even 61cm.

is your brother michael phelps? lolz


also, performance sells good ss/fg bikes but they also sell some pigs that really kinda suck. i'd suggest against the se draft. most of their bikes under 350 are kinda crap. they may say you can only get the one i linked to online, some stores have them and some don't.