I'm currently using a Tamron 90/2.8 macro on a Digital Rebel XTi, mostly shooting rings, pendants and watches. I'm going to need to start shooting larger tabletop setups, and I can't use this macro prime without moving back halfway across my studio. The only other lens currently at my disposal is the Canon EF-S 18-55/5.6 kit lens. What are my options? Should I be looking a normal prime lens like the Sigma 30/1.4? Or a shorter macro like the Canon EF-S 60/2.8? Something in between?