Hi Tony, to me that woud normally sound like a pre loved ED in the 60-80mm class. Something like this:
http://www.iceinspace.com.au/forum/s...d.php?t=140526
Your EPs would work with that, even if it only had 1.25" fittings. The 25mm will be fine for wider views.
A short tube achro may be OK too, but both Saturn and Mars will be well placed and worth a look and you might want a bit more power for these than a short achro would comfortably allow.
Problem is that you are going to a dusty environment, and with that in mind, I'd probably just get a small newt around 100-130mm of aperture with a parabolic mirror and maybe around f/5-f/6. You have at least 3 eyepieces that will work really well on DSOs at that f ratio. Small newts such as the SW Heritage 130 are cheap plus can be cleaned of dust much more easily than a frac. I'd hate to have to clean desert grit off an ED objective. A mirror you can just stick in the sink when you get home.