It really depends on how far you want to go. Headunits can range from $100-1000 depending on what features you want. Unfortunately there is a big shortage on headunits right now so it will be hard to find one in stock.
Crutchfield is an online store so no installation from them.
Your budget will be the biggest thing.
You could do
JVC M150BT headunit $200
Infinity 6004a 4 channel amp $189
Infinity reference 6530cx front component speakers $150
Infinity 6532ex rear speakers $75
8 gauge wiring kit $40
4 channel rcas $20
and all the headunit install harnesses and steering wheel control adapter $80
$750. This is all decent lower budget equipment.
Are you wanting subwoofers as well?