Can I purchase a textured sleeve in different sizes?

No, these are fixed sizes. You may however choose different orifice and colors. The  Wonder Wave,  Speed Bump, and  Super Ribbed sleeves are all considered 'super tight' in the sense that each canal is roughly 1/2 inch (13 mm). These are NOT available in the original 3/4 inch (19 mm) or ultra tight 1/4 inch (10 mm) diameter canal. Each varies slightly dependent upon the texture of the inner canal.