Need help with 1968 Ford Mustang Coupe sound system setup
 

Hello. I am currently restoring a '68 Mustang coupe and I would like to upgrade the audio system when its done. I'll list everything that I know I'm getting so far, but my question is what amplifier should I buy? Also, is the in-dash speaker below a good choice? (Looking for a quality 5x7 speaker under $70) Please let me know if I'm missing anything else too. I'm not looking to have the most high end system. I just want something that is decent and will last. Thank you!

Head Unit (already have it):

Custom Autosound Mustang USA-1 Radio Chrome Face 1967-1973

In-Dash Speaker (possible purchase):



Rear Deck Speakers (already have 2 of them):

Lightning Audio B3.69.3 (b3693) 225W Max, 3-way 6" x 9" Speakers

Single Subwoofer (already have it):