I picked up a 65 Mustang tank with the electric pump already in it from Amazon of all places. It dropped right into my 63 except I had to get creative* with the filler neck (Mustang is aligned with the gas cap whereas 63 Comet is offset). It is made in Canada, so not the normal Chinese-made crap you might find on Amazon. I am sure you can find it elsewhere if not a fan of Amazon.
*Getting "creative" involved making a carefully timed trip to the beer fridge while my older, smarter brother solved the filler neck alignment issue.

The company that makes the tank, Spectra, sells the pump assembly separately. It mimics the stock pickup and sending unit assembly except there is also an electrical connector for the pump. I checked their website this morning and found the assembly here: https://ecat.spectrapremium.com/products/SP169A1H
Note that this is for fuel injection, so keep that in mind. It has a high pressure pump.
If you need a tank, too Amazon calls it: "Spectra Premium F28AFI Classic Injection Fuel Tank". Spectra just calls it "F28AFI".