I have a couple of the tanks with the grooves in them and they are great for profiles but as far as I know they are supplied with the arfs by the manufacturer ( chinese) and are not available from any of the U.S. suppliers. A good tank for a profile is the Sullivan Slant Oval tank.
Here is a link to the 8oz tank but they have other sizes available.
http://www2.towerhobbies.com/cgi-bin...?&I=LXFU57&P=7
Dale