The 40mm will be a useless EP as the FOV of it is really limited. 32mm is about as large for the 1.25" size and for a widefield EP, something more like 20mm is about as large to have the full field. FWIW, Nagler's EPs are almost all 2" designs because the 70deg. apparent FOV requires that much real FOV in order to not vignette.
I'd probably go with a 25mm and a 8mm for one setup as this will give 25, 12, 8, 4 for the sizes. A 28 or 32 could replace the 25 if desired. Also look at the max magnification (2x dia. in mm) of the scope and make the shortest EP + barlow near that value.