Christian at Gulf Coast Gun in Milton has done sight installs for me, always does a good job and he's pretty fast. I've also had some done at Grey Man - the turnaround was a bit long but the work was good.
If you can't find anyone near you, I have the wheeler sight tool and have done 20+ Sigs. But since you're new and this is your first post on the forum, I'll meet you somewhere near me to install it for you for free.