Replacing windows on brick house, need advice.

Looking to replace cheap windows I installed 18 years ago and need some tips and advice.

https://imgur.com/a/Jr7Kkcb

Made the mistake of buying cheap windows and have finally come to the financial realization they should be replaced with something better suited for the cold north east climate.

I work with various builders and have pretty much been recommended Marvin windows. One question I have is I have a single story house why wouldn’t I go for single hung over double? Wouldn’t it have less area of air infiltration? But I don’t see any premium single hung options.

Also curious is aluminum/wood the better option over fiberglass/wood?

Next I’d end up replacing the wood surrounding the windows with something more maintenance free. The inconsistencies of the brick edge made this difficult for a non carpenter like myself to get a nice tight edge as to avoid having to use to much caulk. What are my options? I really don’t like the look of doing aluminum and have heard of hardi but have no experience with the product or its installation.

And lastly as far as interior finish. These widows were installed and then I installed casing to said windows. I checked Marvin’s single hung dimensions and it looks like 2” from exterior flange to inside edge which is what I have now. So there’s a good chance I might not have to re-case every window?