I'm one of the audio sponsors here on the forum. I recommends you Run a search and see what other folks here have installed on their bikes and that should give you some ideas. Really comes down to how mild or how wild you want to get. Lots of good options out there!!
I have been ready to get audio for awhile but not sure where to order. Tell me where you have and your experience.
Working with a sled stereo company like Bagger Audio Labs will help you make good decisions and not waste money and time installing equipment that does not perform well on our sleds.
BaggerAudioLab will be where I spend my hard earned money for all of my audio needs without hesitation. What kind of setup are you looking for? There are quite a few happy customers on here that can share their experience with the type of setup you want.
Personally I have a full pro audio setup: 6.5s and horns in the fairing, 8s and horns in the lids, 8s in the bags, 3 amps, and a DSP.