If you want a smooth canvas look, check some fine art papers. Buy some samples packs, itsupplies.com has a good selection. Hahnmuhle and Canson have some very nice paper textures that sort of invoke the canvas genre. For a very fine, canvasy texture Hahnemuhle Albrecht Dürer paper comes to mind. It's light weight and would be easy to wrap around a panel, if that's of interest. Both Monet and Daguerre canvases are reasonably smooth with a very attractive, not-too-polarized texture, and so is Hahn Photo Canvas 320.