What size canopy camper shell?

I have an 01 DC and a full family. I have a truxedo tonnou and like it alot more than the hard covers I had in the past but could use even more room when shopping and traveling with the family continuing and the threat of my tween step-daughter moving in. I have been looking for a canopy / camper shell but have had little luck. Some are advertised by dimensions in inches. Can someone tell me what dimensions I should be looking for of what other trucks share a compatible size?

 

So far as I know, the 2001 - 2004 Taco DC bed dimensions are not the same as any other pickup's. You'll need to find a canopy designed for the Tacoma DC.