Before you build the cage, you might ask around a little more. I think it was PHEve who had an Egyptian and a Saharan who got along famously for a long time until one day for no obvious reason the Egyptian picked up the Saharan in its jaws, shook it like a ragdoll, and flung it across the room. I believe there were no permanent injuries, but it just as easily could have ended with a dead Saharan.
Things can seem fine for years and then suddenly go horribly wrong. It's bad enough with similar sized species, but soon that Egyptian will outweigh your Saharan by about four times over, and the potential for injury or death increases greatly.
They don't need cagemates for "happimess". So, if you really care about the wellbeing of your critters, I would recommend permanent separate enclosures.
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Torey
Eugene, Oregon, USA
1.1 Saharan Uros (Joe and Arthur)
3.1 Mali Uros (Spike, Turtle, Tank, and Lilly)
1.1 Ornate Uros (Scuttlebutt and Shazzbot)
0.1 Collared Lizard (Rorschach)
2.1 Green Anoles (Bowser, Sprocket, Leeloo)
1.1 Chubby Housecats (Roscolux and Jenny)
