I recently arrived from Germany, and love our Swiss made SIGG metal water bottles. They are great for here. Surprised to see them recently in front of a small health food store, right next to the Balloon Shop at Springs Town Centre Opposite the ATMs). They are not cheap, but very good quality!
<em>edited by SuzyDuzy on 12/07/2011</em>
Having tried pretty much every water bottle in Dubai over the last few years, I recently found Thermos metal water bottles in Jashanmal at Wafi (it was closing down though there are other branches). They're the best we've had so far, they don't leak and if I leave mine in the car the water's still cold when I get back!
We use the small plastic clip lock boxes inside one of the small, hard coleman cool boxes. They seem to keep the food cooler than the soft bags.
There is a real gap in the market for a firm to actually design a leak proof bottle because no matter what their claims, they don't last with the amount their used here.
An alternative to the metal type, if you don't find one, would be the small insulated thermal bags, you will find a range of them in Daiso for about 7 dhs, one of those would keep the food cool better than a metal or plastic one too.
Carrefour and Lulus have (well did have before I left eight months ago) the metal water bottles, but haven't seen metal lunch boxes. I found the choice of lunchboxes in Dubai pretty poor.