As far as UL and the NEC care, this is no difference between a panelboard and a load center.
For your installation, the only major differences include: Load centers are designed to fit inside of stud cavities so they are about 3-1/2" d and 14"w. Panelboards cabineets are usually 5-3/4"d and 20"w.
Loadcenters breakers are normally plug-in style while panelboards are more often, but not always (i.e. NQB), bolt-in style.
