Good on you Barry. Join the portable EAA frat.
Your budget/pref is the Orion tracker which is Alt Az so you will be limited to short exposures and therefore not chasing AP quality.
Your budget/pref is to keep using the Infinity camera on it. It is also not AP quality, but built for EAA use.
So if I were you, I would not worry at all about folk saying you need to get true triplet APO quality and expense. Very much overkill IMO when it's to be used on portable lightweight low carrying capacity Alt Az mount like the orion tracker. Plus also very much overkill when it's to be used with an Infinity OSC.
And of course, the whole idea is portability ... so carry it out the back, travel on planes, trains and automobiles or even short hikes, then the last thing I'd want is an expensive Apo to worry about damaging.
IMO a doublet ED80 (if its not too heavy for the Tracker mount?) will more than suffice. Google on Astrobin and the web to see many use doublets for true AP work. IE far better images than any images we get doing even fixed pier observatory based EAA. Far better images than even those doing EAA who happen to use true CDD imagers So again, I would not worry at all about triplet of quad or more high end fracs.
BTW, for the record there are many who get second hand ST80 with bad CA and simply use wratten yellow #8 filters cure CA and UV/IR filters to cure bloat. Still lets in more Ha than a normal IR filter so you get nebulosity goodness. But the yellow #8 filters are cheap to fix CA. See this post ...
But ... filters add to the list of more stuff to take out and about and potentially loose, and do reduce the amount of light and potentially have weird optic aberations and most importantly add to the cheap cost of an ST80 making its total cost nearly the same as a ED80 doublet!!
So if I were you I'd go the ED doublet path .... it will work nicely with the Infinity and Tracker and not costs heaps and not be too much of a worry about transit damage and be lighter weight, etc.
BTW, 12dstring FOV calc website will let you test 110 messier and all planets showing many combos of scope and camera and both yours are in there. Here's M42 and M57 and M13 thru that combo of Orion ED80 and Infinity
Edited by Howie1, 24 May 2018 - 03:46 PM.