I'm building some Rhoboats, and here's what I have so far:

Rho Sqd Pilot: Deadeye, Plasma Torps, Chips, XG-1, Jamming Beam.

I want to give it either Clusters or Harpoons, but which is better for firing every other turn (allowing to reload)?

I kind of like mixing the ranges. Clusters can cover you at Range 1. It's a shame there isn't a better short-range Torpedo to replace Plasma. If there was a vanilla 4-dice range 1-2 torp for 3 points, I'd run that and Harpoon.

I'm not sold on Jamming Beam, though. I think I'd probably rather have Tractor or find a point for Flechette to actually do damage. I could be wrong about Jamming Beam, but it looks weak to me.

Nu-Boats have potential, too. Four with XG-1, LRS, Harpoon, Flechette Cannon.

My Rhoboat squads have been a little... different then the norm:

I think throw a bit more on the Rhoboats. Deadeye, Adv. SLAM, Flechette Canon, Proton Torps, Cluster Missiles. It lets you still deal damage when SLAMming or reloading, and when you can fire the ordinance, you have all ranges covered. I might consider pairing it with Cpt. Jonus to give some re-rolls on the ordinance shots. Maybe throw Fleet Officer or Kylo Ren with Rebel Captive on.