Seems like a wealth of good info has already been offered. I'm no professional just a guy who replaced the whole system in my TRD pro last week.

That said, I would absolutely axe the LC and go for a headunit. You're investing a fair amount of cash and the oem headunit is going to be the Achilles heel until it's removed.

Yeah, you have to get a dash kit painted by a local collision schop. Good news, it only costs ~60 bucks.

I'm running pioneer 8200nex, focal krx2 components in the front, focal access 6.5 coax in the rear doors, JL dual 8" micro sub box off a JL 900/5 amp. Sound is just what I wanted. Loud, clean, just enough low to fill out the sound without rattling the streets. Also dynamat four doors plus hatch.

I was building a system based on the stock headunit as well with nearly identical components. Both top local shops talked me out of using focals or c5s/c7s without swapping the head untit. They said it was like setting money on fire.