Need help wiring 4, 3 ohm speakers.

I have 4 Polk MM651UM speakers that are 3 ohms each.
I am wanting to power them with my Rockford P500-2 amp that''s rated at 125W x 2 @ 4 ohms. 250W x 2 @ 2 ohms, and 500W x 1 @ 4 ohms.
Two speakers are in a double tower speaker can, with one set of out output wire terminals.
Right now the speakers are wired in parallel, which drops them to 1.5 ohms, which I think is too low for the amp, and might cause some problems.

If I wire them in series they will be at 6 ohms. Any idea what kind of power the speakers might see at 6 ohms? And is that safe for the amp?

I was also thinking about wiring them in series inside the cans, then hooking them up in parallel at the amp. Only problem is that it will be one channel at 3 ohms, not sure if the amp can do this.

Why on earth doesn't Polk make speakers with normal impedances.....