The monk at our table used a quarterstaff in lower levels to get d8 attack dice for the primary attack while using the unarmed strike (kick, head butt, etc) for the bonus action unarmed attack(s). As [MENTION=13009]Paraxis[/MENTION] pointed out, monks just get to use monk weapons and unarmed strikes for their attacks. It makes no distinction about weapons in which hand or anything like that. So wield two short swords that have different magical effects and split your die rolls between them if you want to. Or use a two handed quarterstaff at level 1 and d4 kicks for the unarmed strike bonus attack(s). Unarmed strike is not limited to punches (at least not for the monk), so the monk does not need its hands free.