Audio Questions

I know this isn't the typical question to ask, but I need to buy a sub, and possibly 2 amps for my XJ. I have 2 Hertz in the doors already but they have no power to them. The XJ is wired already so I just need to get the amps and Sub. I am not trying to go crazy and don't want to spend a ton since this is not my daily driver and only for good times. Any suggestions? There is too much out there and all kinds of different opinions. I am thinking about 1 12" Sub, and either 1 2-channel amp and 1 Mono OR 1 3-channel amp. Any help would be nice. Thanks!