Thanks for your tips. Soon I will purchase a RASA 8 for EAA and general deep sky astrophotography. Working on what goes with it. In some YouTube videos, RASA users have large Finder/Tracking scopes, so I am exploring what and why. One consideration is a dual use of the tracking scope. Can I package the RASA 8 with say a 60 or 70 sized refractor which can be used for tracking, and also as a stand alone grab and go portable scope. Comments if this would work, or be of benefit vs buying a smaller tracking scope, or none at all. In other words while the RASA requirements are a high consideration, dual use of the camera, finder/tracking and filters is also.
Once you get a RASA, question is what else do you really need! Ignoring cameras, discussed above ---
I use AVX entry level mount. With an aftermarket 7.5 pound weight from Orion. With something like RASA you do NOT need a finder, guide scope, starsense or any other gadget. Just do rough polar, and plate solve. With thousands of stars visible, plate solving is trivial, and works from within Sharpcap Pro using ASTAP or Astrotortilla.
For humidity control, I really love the Pegasus auto-controller with temperature and humidity sensor. Simply perfect. The basic roll up dew shield, although i keep thinking i should improve on that some time.
A mini PC for mount and camera control. I recently got a Ryzen powerhouse and it simply rocks.
A plastic tupperware box and some 10 dollar 12-V power supplies from Amazon. I need 4 at 12V (RASA fan, camera fan, Pegasus humidity control, mount) and 1 at 19V for the mini PC.
I use Polemaster for polar align. I got that before I got into EAA, and still love it. Since i observe from the same spot in the backyard, takes me less than a minute now.
A 3 ft long high speed USB 3.0 extender to work with the 6 ft OEM cable from ZWO.
A Flatman light box for flats. Helps with larger sensors. Takes 2 to 3 mins all in using Sharpcap Pro.
A light polution filter -- Celestron makes one for RASA that replaces the clear glass window. I also got an Optolong Pro to compare. But that needs a filter adapter, you cannot just place it in the RASA window.
A nebula filter if you wish, given the photons you can unleash at F2 with a wide field. I got the new Quad, makes EAA images look like they belong in an AP folder.
A tri bahtinov mask for precise focusing and visual confirmation of focus and collimation / backfocus.
Then you can also add after market adapters. I am currently using the Starizona filter drawer, which gives me choices to use different filters.
Some Baader or similar spacer rings. Backfocus is one of the most critical items of image quality in a fast widefield system. I use a 0.3mm ring on top of recommended spacing to nail the star quality. When I add filters, i may need a bit more depending on what i do with the clear glass window - keep or remove.
If you like to tinker with imaging quality, a program like CCD Inspector or others to inspect curvature and tilt, most of which is resolved by nailing backfocus. Very handy. Take snapshots with Sharpcap Pro and do instant checks on image quality.
I am now considering the final step -- auto focusing. Not because the RASA needs frequent focusing. For EAA, the focuser is so good, you can set it once and generally be done unless big changes in temp and seeing over a long duration. But as a final step / improvement in image quality, using the entire star field or a big part of the ROI to nail focus is quite appealing! Machines can focus better than I think I can manually with a mask. I am not there yet, just pondering, learning.
Hopefully this gives you a perspective of what else you can consider over time! In reality you need very little to get going -- besides the mount, power supplies, and a PC of some sort to manage the EAA.