The ViewStar is a good controller. Be a shame to dump that. You could keep that 10amp one and get any $15 controller on eBay to run another 50w panel.
150w should net you 150/130 x 8.2 amps = 9.5a aimed at a high sun. That does not leave enough margin for a 10a controller. The usual advice is to allow 1.25 more amps for the controller size.
You could get another (single) 100w panel and have two 100w sets and get another controller (an RJ Special for $15 on eBay) for the second 100w panel.
That should keep you busy for a while as a new solar addict :) Or if you have the urge to buy more solar, just lie down until the feeling goes away!