Alright guys just an update with more questions.

Got the REV10s on order last night(X-Mount with the adapters.)
SNY-4 at the house.

Will probably do the Sub and WS420 at the end of the season.

1) Do you guys think I absolutely need a second battery now. Ordered the boat with one battery to save on the price as I can always add one later. I know once I get the sub in a battery will be going with it but do I need one now. Will currently have 6 inboats with factory amp the SNY-4 and the REV10s.

2) Best speaker wire for the REVs 12 or 14 gauge tinned? Any links with a good price?

3) Best amp wiring? Guessing 4 gauge and what size fuse will it need.

Any other no brainers I will need to get this all up and running?
Automatic Charging Relay? Boat will be hooked up to a trickle charger every night.

Power distribution blocks?

Good RCAs?

Thanks in advance as this has become and all new learning experience.