Ditto to pretty much what everyone had said. Holy cow you guys actually take measurements??!! n in metric system?!!!
Anyways, if you want to minimize sanding or EVEN painting, aside from PG kits, there are three MG (all are 1/100 in scale) kits that might work out better, RX-79[G], RX-79[G]Ez-8, and the GM which pretty much shares most of the parts. All the armor pieces are slide-molded in one piece so there is no seams to be filled.
Aside from that, smaller HGUC kits make a quick and fun build yet still carrying really good fitment and pretty good details. the line also features a lot of the never been released mechs, from the one year war, 0080, 0083, Zeta, Sentinels, all having a vast increase in quality as opposed to the older kits released for those anime series.