Was always told magnesium malate was the one you want if you don't want to get sleepy. Was the choice by pro bodybuilders I've rubbed elbows with.
Discussion
Citrate and glycinate are good because they absorb better, I use them more in a clinical setting. Malate is good too.
Yeah, I use citrate myself but I use it for the stool benefits you mentioned.
I just know when I used to train in a bodybuilding gym, they would often include that in their pre-workout stacks.