Couple of things or two I'd like to add.
Sound deadening.
-For a really good sounding vehicle interior, just the actual 'interior', killer sound system or nothing at all, sound deadening really helps these trucks! It makes them feel more solid. Takes away a lot of squeeks & rattles. It's not cheep to do a whole interior, especially the bigger ones, but it can be done in stages. Did mine this way, 'cause it's my DD. In this order. On different days. Doors, backwall, headliner & pillars, then the floor. I did all of it with the interior in the truck. Left the floor till last cause it took the longest to do, & required pulling the seat. I can do that all day on someone else's vehicle, just a PITA to do it on mine!
When you install the new speakers, spend the extra time & $$$ to at least do the doors. 65-70% of interior road noise is via the doors! I've posted pix of that somewhere on the forum.
Install stuff.
Run the power/ground from the battery along each side of the tunnel to the amp.
That can be installed either in the console, under the seat, or behind them on the wall. If using multi-amps, use a distribution block as close as possible to the amps. A dist. block can be used to power other stuff in your vehicle too.
Use a bigger 'kit' than what you need. If your system requires 8ga, use the 4ga kit. Not only is the larger wire more efficient, but if you ever want to upgrade, & you will!, you don't have to go through all the wiring B.S. again!
Check the wire core of the wire too. Cheap off-shore stuff has a thicker plastic covering hiding wire that just may be undersize!
Use automotive speaker,ground/power wires! The really good stuff, read $$$!!!,says 'oxygen free' on it! ooohh! No house speaker wire!
Always wire your speakers in the proper polarity. +>+, ->-. Some wires are marked as such, some are colored. Red & black, or copper & silver. Some aren't marked, but one side will have a ridge. Black, copper, or the ridge is ground or neg.
If you use the push on ends at the speaker end, whatever they're called, IIRC the larger tab on the speaker is +.
Keep the speaker wires as far away as possible from the power/grounds by running them down each side of the tunnel.
Use the door sills for the speaker wire.
Oh yea! Focals!!! But at $1500.00 for a pair of 6.5's? They damn well better make me say "WOW"!!! Holy Crap!
That's all I can think of right now. But you never know! Lol!