Mill Max are very expensive and a pain to solder each one in. On top of that it will only work with certain thicknesses of switch legs. You can use 3 pin or 5 pin mx switches, it doesn't matter. If the pcb doesn't have the holes for 5 pin, just cut off the plastic legs on the switch with a flush cutter or exacto knife. KDBFans has hotswap boards, otherwise if you want to go higher end the Rama U80a is a TKL with hotswap.