I’ll try not to be redundant with Danny, here:
I've been reading the forum and trying to decipher the best place to install the facet fuel pump?
In my opinion, the best place to install a Facet fuel pump is in the trash bin. They pump OK, but in pulses and they make one helluva lot of noise - clack, clack, clack…….
Should I install it after the filter and on that shelf below the fuel tank?
Yes - That’s a great spot, and after the fuel filter.
Also, I've heard it can be quite loud and people mount it on rubber? Wondering what you may recommend for that? See the trash bin comment, above. You might have noticed that neither Danny nor I are Facet pump fanboys. 
Also, it seems to be like there is some debate as to it vs the CB rotary pump. So wondering if maybe I should install one of those instead...
YES! On the same shelf in front of the passenger footwell. We believe that the CB pump is made/sold by Carter so you might find a Carter equivalent for a few less bucks or just order the CB pump and carry on.
I did buy the Malpassi filter king regulator due to a friend's recommendation as well, can I still install that in the engine compartment on the firewall?
Sure. It would actually partially smooth out the pulses of the Facet pump but it will regulate the CB (or Carter equivalent) pump, too.
The fuel filter I used is a NAPA Gold 3031. It is metal cased and mounted in-line between the gas tank and the pump, on the shelf immediately forward of the passenger foot well, and forward of the body bulkhead. It is mounted with a large, neoprene-insulated electrical clamp to hold it down - The same type of clamp I used to secure the fuel pump. There is no further fuel filtration except for fuel strainers at each carburetor’s inlet (inside of the Banjo fitting).