Power wise, there's lots of options at various price points, the key is making sure what you get can provide enough current to support what you want to run. Less expensive power supplies may scrimp on filtering (read, interference) or features. Dx engineering has a few options here link while se of the Tekpower on Amazon are well regarded as well.
Antenna wise, indoors or outside below roofline are varying levels of less than ideal, but that doesn't mean they won't work to some extent. Haven't tested simplex, but I get into the local repeater fine with a small 5/8 wave whip indoors on a bookcase, mag mounted on a piece of sheet metal.