New Speakers for Aristo Power

Hi all,
I am in the process of installing QSI Sound/DCC control on all my Aristo power. That consists of a Mallet, Pacific, E-8, Fa-1, FB-1,U-25, and Dash-9’s.
I would like to know what the best/largest sounding speakers that will fit in each Model are and where to get them.
I would also like to know if anyone has had any experiance with this company “1 to 1 Scale Sound” it appears to sound good, am wondering on fit in some of my engines, here is the link for them https://home.comcast.net/~leonardk12/rrbog/1%20to%201%20Scale%20Sound.html .

I know that I am asking a lot so no need to answer for every type, but if people could chime in on one or two types that they have most experiance with eventually I’d get the info I seek.

Thanks in advance for your help, Ron

Any Good quality speaker will be ok. The sound card is the item that needs to be of good quality I use pheonix sound and would recomend that 100%.