Jackson's Chams are one of the koolest chams! Glad to hear you are getting one. It sounds like you've done a bit of research on them.
I housed my Dwarf Jackson's (Chamaeleo (Trioceros) jacksonii merumontanus) in a 18x18x36 all mesh enclosure. If you are getting a regular sized one (Chamaeleo (Trioceros) jacksonii xantholophus) I would consider using a cage that is 24x24x48. For the Jackson's... do try and get/make a cage that has 4 sides being screened. They do like it a bit colder than most chameleons.
If you haven't checked it out yet, here is a good link for basic Jackson's info:
http://www.adcham.com/html/taxonomy/...sonixanth.html
Unfortunately I do not have any pics of my cages yet. Beware listers.... I'm getting a digicam next week and I'll be posting pics of my chams like MAD!
Please post some pics when you get the little guy!
Actually Dom.... Jackson's are considered a good beginner chameleon.
Cheers!
Trace