Both Coronado and Lunt can supply external Ha etalons.
https://luntsolarsystems.com/filters/
https://www.meade.com/solar.html
You then need an additional blocking filter either a 10mm or 15mm size.
You just need to find/ manufacture a suitable adaptor plate for the scope.
(I use an SM60 on an ED80 - works very well)
Hope this helps.