Innovative accelerator-based production routes for Mo-99 (and Tc-99m) have been studied, comparing the Mo-100(p,x)Mo-99,Tc-99m and Zr-96(alpha,n)Mo-99 reactions, for which a new set of measurement has been made. Theoretical and experimental cross sections have been analysed and used to calculate Mo-99 production yields and specific activity (SA), considering fully enriched and commercially available target materials. Results show that the low SA resulting from the p-based route forces the use of alternative generator systems, while the alpha-based reaction provides very high SA Mo-99 but much lower yield. Benefits and drawbacks of direct Tc-99m production via the Mo-100(p,2p) reaction are also discussed.