Can this part be done in a two part mold?

Actually since you have a flat side, you could almost do a simple one piece mold with the other flat side as the pour area and make sure to either cut the mold itself to release the holes inside or make an indention and drill/cut the holes out afterwards. That's actually not a very complex/complicated shape even with the holes, try a posed action figure in a frozen action pose and THAT would be a challenge.

If you go with a two piece mold, I'd make sure to use a couple pieces of wood to sandwich the mold to give it even holding pressure. And personally I use Velcro strips instead of rubber bands. Also you don't have to use pressure casting if you don't have the right equipment (I've never had any problem not doing it) but I do agree with a slow set resin.