Welcome aboard indeed! Its great to see another modeler who has an interest in the Vietnam war of figures and armor! That is certainly a small crew in most sites or clubs. I do like your figure work as well.
I can't speak for any of the Tamiya M4A3E8 builds aside from their original issue from when Christ was a Corporal, but their Cromwell kit is the epitome of a joy to build. There are no speed bumps engineered into that kit. it has been one of my favorite armor builds for its ease, speed, and quality of detail. I ran into problems with the tracks on mine during painting, but that just could be me and my use of mediums.