What guitar amp should I get?

I have been playing electric guitar for a couple of months and I really want to get an amp. I have been using a my b amp that I have since I play b and I have also used my sisters fender g deck. So I am looking for something to learn on but at the same time have something that my sister can use (she has been playing for about five years mainly acoustic) I listen to a lot of rock both clic and the newer stuff and a little bit of country but if I had to choose I want something with more of a rock tone (I know i'll need pedals to get a good rock tone but ill deal with that later). So you have an idea of what I'm working with I have a fender deluxe power strat and about $300 but I also have a fender 400 pro and 210 pro cab for my b that I would be willing to sell/trade if it meant getting a lot better guitar amp. thanks for the help