Actually you want to go to Luxury ave. by Kukulcan Plaza in the Hotel zone... Louis Vuitton, Cartier, Fendi, Montblanc, Tous, Swarovski, LladrĂ³, Longchamp, Salvatore Ferragamo, Swatch, Chopard, Tiffany Plaza La Isla Mall sells high end items as well
I think you might be thinking of what they call Luxury Ave in the Kukulcan Mall. La Isla does have some high end stores as well but the truly high end stores are in Kukulcan Mall.
The Oasis is at KM 16 or thereabouts. The Kukulcan mall is at KM 13...beside the Tucancun like apple said. So it's not to far at all.
There is also a Rolex store in the mall, I was there one time and asked what the most expensive watch was (not like I was gonna buy it but curious) it was 100,000USD. When I went back a year later I went to see if it was still there and some rich bastard bought it up before I could, lol.
you can bring drinks on the bus! On every trip I have made to cancun, I bring drinks on the bus EVERY time and have yet to have a problem!!