This is what I did for my 6" GSO Classical Cassegrain. Roadcasesusa.com has a section on their webpage where they will make you a case for 99.00 plus shipping as long as the length, width and depth to not add to over 100 inches. The case is really well constructed. You make your order over the phone telling them how you would like it constructed. I just told them the internal dimensions I needed. I opted for a removable top in lieu of hinged. It's carpet lined and it has flush latches. I know it's a little more than the tool box options, but this case will last a very long time.
For now, I just cut sections of the shipping foam that the scope came in to support it inside the box. I can always cut some Kaizen foam for a more durable support solution.
Edited by cturek, 09 June 2019 - 12:53 PM.