There are a butt ton of "good" to "great" speaker recommendations that can be made. My ears aren't good enough to hear the difference between decent and fantastic sound anyway so paying big bucks for speakers doesn't really help me. Our radios aren't the hottest output device in the world anyway so, again, just "good" speakers were always good enough for me. Anymore I hardly ever play the radio when I'm riding anyway. Prefer the sounds of the road.
In any case, some good marine speaker (I often used some Polk Audio) options are out there for not a ton of expense. You may receive lots of other very good recommendations though. Whatever you end up going be sure and take a look at a couple things when you go inside the fairing. There's a little horizontal bracket that helps support the speaker. They occasionally break. And the large vertical bracket that supports the fairing itself broke with some regularity. The latter broke often enough that Harley revised the part. There are some significantly more expensive aftermarket options for those brackets. The later revision of the Harley part does ok though (and for a fair bit less money) if you need them. Just something to keep an eye out for while you're in there.