You may want to look at a pair of 4 1/4" 2-way JL Audio speakers.
You may find them at "high end" car stereo installers,...but they are not very costly and they sound great.
Remember to cover your speaker enclosures with "Dyna Mat" to reduce unwanted harmonics.
Momz, I have Alpine speakers on my I/S. I didn't reuse the Honda enclosures in the fairing. I lined the inside surface of the fairing and the back side of the speaker panels with DynaMat. Sounds better without the enclosures.