ExplorOz Team replied:

Ormiston Gorge is delightful and has many options for camping/walking etc. Glen Helen caters less for self-sufficent types and more for guests of the lodge. Ross River Homestead is rather commercial in my opionion but it is a lovely building, with a kiddies farm and activities. Of the 3 options it will cost the most. No problem taking a caravan to these areas - tar all the way from Alice to Glen Helen (short hard formed dirt access tracks off the main route to each gorge area). Please read our notes on the West McDonnell Ranges in the NT trek notes on this site.

stephen mills replied:

all ok but try redbank gorge a little further west, nice and quiet, toilets etc and wildlife abounds- just a little more private than the others! if you know what i mean
steve