Proposed build for a 97 Jeep Cherokee. The 80prs head unit. Polk DB6501 components in front doors and the Polk DB521 in the rear soundbar. Need a good, clean cheaper amp.

I am a novice and not sure which speakers to hook up to which RCA outputs on the HU. AND, if I use the RCA jacks I can then use the network mode and set the crossovers via the HU. If so what do I do with the crossovers that come with the components?

Any other suggestions or pointers would be appreciated.