Seeking advice on good planetary telescope recommendations

Didn’t mean to demean your very valid question with such a trite answer so let me expand a bit on it. If you look at the best amateur examples, here on the bin and elseware you’ll see why I picked that aperture range. I don’t know if some professional experiments have been done on much larger apertures but for the most part, that’s what you’re looking at. I have to laugh sometimes when I see 7” macs being marketed as “planet killers”. They can do well for the aperture but I wouldn’t get one if I wanted to specialize in the field.

Given the aperture range, you are most likely looking at a Dobsonian as the most practical solution, hopefully with an excellent mirror. A small obstruction will help with contrast a bit but it’s the resolution power of the large aperture that does the heavy lifting.

The last thing is seeing, Thanks to lucky imaging it doesn’t need to be perfect but it does need to be good. We often talk about average seeing in the deep sky world but that doesn’t tell you much about what’s happening on the scale of milliseconds. Displacement isn’t as bad as de-focus but it’s highly variable. You can monitor what you’re getting for hours only to get maybe 30 seconds when everything magically calms down and the fine details become visible. Old visual observers can tell you all about that. I would certainly take a hard look it the seeing throughout the year from the site you intend to use. It might be great (not likely) or it might be unusable (very likely).

Hope that helps and good luck with your explorations!