I'm looking for gladiator style sandals, but with decent arch support as I have flat feet. argh... so frustrating, all the ones I like are super flat soles, even a tiny wedge heal would work in lieu of an arch support!
Try Ecco. Their shoes are little more sensible for our old lady feet. you need to check the "old lady" type stores if you want things with "support".
Walking on a Cloud is one shoe store that comes to mind with more "support" type shoes. not cheap tho.
or you could probably get some sort of arch support orthodics to put in them.
There's a place on the north side of Queen just west of MacDonell in Parkdale that sells stilettos of all things with orthotics built-in along with a huge assortment of other shoe styles. Didn't notice any gladiator sandals, but then again, they're not my style so I wouldn't have looked for them (neither are stilettos, just couldn't believe orthotics could be used with them!). It's a relatively new shop and I'm having no luck with google tonight so will get a name at least on my walk-by tomorrow.
If nothing else, someone at some point may require 5 inch spike heels with orthotics!