My bike currently has SRAM Attack gripshifts. According to Specialized.com, it originally had Shimano R440, 9-speed STI shifters. I'm trying to find out what other shifters would work on my bike. It has a Shimano FD-R443 Tiagra front derailleur and a Shimano Tiagra long cage rear derailleur. I'm a newbie at all things bicycle, so I have no clue other than they have to be compatible with the gearing (9-speed rear, 3 in the front). Could anybody shed some light on the subject and help me determine my best options? Thanks.