I did think about a Rumble 115, cheaper and lighter than the other options discussed. However, for all the positive reviews there are also quite a few negative ones.
I asked JeezyMcNuggles on Youtube about standalone cabs as he has vids on the ABM 115h, 210h and SVT112. He prefers the 210, over the Ampeg and then the 115, which was interesting.
I was concentrating on the 115 as I initially was looking at the sealed Neo and thought the 115 would be a better match to that design. I will now choose between the SVT112 and ABM210 (non-Neo), both of which I can add to later on as needed.
Thanks for all your help, especially given I can't just rock into a store and compare, and I will let you know which way I go.