So I've thought about an adult, but there's still the adenovirus thing to worry about. Have you had yours tested? I am not sure if it's worth worrying about for a single pet beardie, but I guess that's one of the things holding me back.
No, I haven't had mine tested for adeno, but she has been to the vet a couple of times due to a pseudo-impaction (apparently, she wasn't really impacted, but per the x-ray, it appeared that she had a build-up of chitin in her belly -- perhaps from the supers she was eating, or perhaps from the few mealworms that she'd get to entice her to her salad...either way, all of a sudden, she wasn't eating, wasn't pooping, like she had been -- even when eating way more supers...), and my vet's greater concern was MBD than adeno -- which, I'm guessing he wasn't concerned about adneo because he didn't see any of the signs of it and that I'd had her since she was 4 weeks old and she was living completely on her own. I didn't even have a fecal done on Jolie (my girl) until I took her to the vet in Oct for her pseudo-impaction...which turned out to be all clear, both times.
Nanci got Isabel as an adult -- but I don't know if she had any initial worries about adeno, either, as she got Isabel from a breeder (I believe...). Perhaps ask her about concerns with buying an adult.
By the way...here's my pretty girl...

(You know, not to tempt you or anything...

But she really is loads of fun...!)
This is Jolie, snoozing on my lap when she was undergoing her "treatment" (she was taking a sort-of laxative to help work the stuff out...so, in order to help her poo, I put on my heating pad & she snoozed in my lap while we watched TV...& yes, I did check on the temp to make sure that it didn't get too hot for the girl!):
And, here's the young mademoiselle today -- just now, being a bit snooty...
Thanks for looking!

(Sooooooooo...convinced yet?

)