welcome to Cloudy Nights!
I think the 90mm refractor you have hits a good spot in terms of size/weight for the aperture. Going bigger 127+ will likely require a much better mount which by itself would used your budget.
If you want aperture, there is substitute for a dob in terms of cost to aperture. The 10 or 12" dobs are just an incredible value if you can adjust to the overall size.
What's in the middle? I think the 8" SCT is popular because it fits in between the other two. A compact package with significant aperture. The C8 by itself is 12lbs. The Meade units are a couple lbs more. This might also need a mount upgrade.
You mention a SCT, which I am interested in because of the SCT's smaller size and portability. I have been researching a Celestron 6" SCT over the past few days. I know an 8" SCT would gather more light, but is more expensive of course. Does an SCT provide a good view of DSOs? Or does a SCT have a narrow FOV? I know this is a refractor forum, but wanted to get more info on a SCT since I am trying to compare to my current 90mm refractor. Thanks.