A tool that can be very useful for planning a new pond is this calculator. I used it to calculate the pond you are thinking about. Those dimensions would net you 14100.45 gallons.

I have personally never made a pond with anything other than pond liner so I don't really have any input on the brick lining.

As far as mostly for yourself and a couple fillets on the weekends. this pond seems much bigger than that. I don't have very much information on bass or catfish, but as far as tilapia you'd be able to stock a few thousand in there.

I suppose if you understocked it you and cycled the fishes ages in you could get a good rhythm going.

This site Lakeway Tilapia (local to me) has been a really good source of information on pretty much anything you could have a question on. Very few videos, but lots of text information on the site. A read through there will definitely reveal some information about trying to do what you are looking to do with tilapia.

Hopefully those links will help you out with your pond planning.

Good luck!