I've been involved in macro for over 40 years now. My suggestion follows Roy's... get your self anything in the 90-105 mm range, NON-IS if possible. IS is seldom, if ever, used for serious macro work, and NEVER used on a tripod.
Any of the modern lenses are sharp beyond your camera's ability to resolve, the only differences these days is price, mostly related to build quality like weatherproofing, etc.
In the mm range mentioned, I've used Canon, Sigma and Tamron. Canon's lens sticks out and is easily damaged, Sigma's is recessed and protected. Canon will make you pay extra for a lens hood (a necessity), one comes with the Sigma; however, newer Sigma's now include IS, which is an unnecessary expense. Tamron remains a good choice.
If you don't want to lug around a tripod,at least get a monopod and a small cheap ball head to put on it. Your image quality will thank you!