I'm not raining on your parade. I've just messed with 12V audio for a long time and have some food for thought.
Do you ride with a windshield? If not, you better plan on something that is off-the-charts loud if you want to hear it at 60 mph with any clarity.
The fairings on the baggers reduce the wind noise significantly — more than even the big detachable shields that you see on a 'King or Heritage. Even with that, you better have pretty efficient speakers and a solid amplifier if you want to hear with any clarity at 60 mph. I use a clarion amp that is a legit rated 75wx4 RMS and you have to push it fairly decent at 65-70 mph. A lot of those cheap units boast high wattage, but in truth, it is a peak number. You have to know the true, RMS (continuous) output to really know anything about the unit.
The other issue is speaker placement. The bagger fairing naturally allows the speaker to be higher and focused inward toward your ears. Where are you going to mount the speakers? If you are running the stock bars, you don't have a lot of options.
Where are going to put the radio? Most of the non-bagger rigs are just an amp and speakers. They are designed to allow you to use any source with an analog output to drive the amp. If you have smart phone, you could rig this using a 12V bluetooth receiver in a way that you'd be wireless and fairly stealth assuming you found somewhere to hide the amp.
Lastly, I will say that you need to manage your expectations about what music should sound like on a motorcycle. I have spent a bunch of money on the stereo in my Ultra and the returns are limited. After replacing speakers, adding a quality amplifier and even trying a high quality, aftermarket head unit, the best listening experience for me is still, by far, wearing my 3/4 helmet and listening through the headset.
2011 Ultra Classic Electra Glide FLHTCU
SE255 Cams | Jackpot 2/1/2 SPC | Jackpot 4" Dyno Tuned Mufflers | DynoJet PowerVision