For years, I used a set of Dell desktop speakers. Now I've got my TV hooked up to the RCA Stereo. It goes up to 30 but I never take it above 15, if that's any indication. Most people think when you're making music that you HAVE to get some huge high-def set of monitors, but that's not true. Sure, you can grab a nice set of Mackie's, but you'd probably be just as good with an RCA Stereo or loud desktop speakers.
Now if you're talking LIVE like you leave your room and go places and need that kind of amp, I don't know if you need an amp head or if you can just use a cabinet with the laptop? I've honestly never tried that. You can tweak the sound coming from your cab with EQ though, so the several cabs I've tested really didn't make too much of a difference for a live setting in the end. People are gonna say I'm crazy for saying that. But with enough tweaking of settings, you can get a good sound from a lot of cabs. My B-52 at-412 sounds great.