At f/15, either of the two 290-based sensors should be close to ideal:
If you want OSC, I'd go with the ZWO ASI290MC - with an IR-cut filter should suffice.
If you're ok with a motorized filter wheel (and filters), then the ZWO ASI290MM ought to do the trick.
I'm not familiar with the focusing mechanism on the CFF - if the default focusing mechanism involves moving any of the mirrors, then I'd also want a motorized Crayford-style focuser. You just don't appreciate how fine a focus control you need until you're trying to achieve fine focus at planetary imaging scales. All the more so if you go the MM route and need to switch filters which may not be perfectly parfocal.
And if you are indeed at a latitude comparable to Seattle, an ADC is another almost-mandatory accessory for good performance on Mars this summer.
Good luck and welcome to the obsession called planetary imaging.
Edited by RedLionNJ, 10 February 2018 - 11:35 AM.