I am attaching a image of the 120mm F 1000mm Skywatcher that I had for a short while. It is mounted on an EQ5 mount and aluminium tripod. I added an RA drive to it for convenient use. As I pointed out and describe, there is considerable chromatic aberration, but this is what the beast looked like. (My current 150mm setup – image above – is much, much heavier.)
For convenience of use, ease of transport, and greater lightgrasp a mid sized Maksutov or Schmidt Cassegrain is the go. The Maksutovs get much more expensive, certainly when larger than 127mm, but if you can manage it weight and size-wise, the 200mm SCTs are relatively affordable. They are quite a versatile instrument with a good amount of lightgrasp. Something of this size is still reasonably portable and large enough that any limitations are not obvious and annoying and should provide years of satisfactory use. The long focal ratio of F10 is great for lunar and planetary. The big question is the mounting where you need to limit any extra weight. For example a mount with a counterweight is ‘dead weight’ to carry up the stairs.