Tuner ream for Gotoh Magnum Lock tuners?

The listing for the Magnums says10mm 13/32" ream, so I'm pretty sure that you want to select the "Planet Waves" tuner ream. The "Gotoh" option on Warmoth is for certain Gotoh vintage style tuners; not all Gotohs. It might be a good idea to call Warmoth and ask as they've probably had other customers with the same question.
I use the Schaller / Sperzel 10mm holes for the Gotoh MG-T tuners. They are a metric product so they are designed to fit a 10mm hole (assuming you want a precise fit). The 13/32" hole may be better if you are going to apply a finish to the neck, and don't want to spend time to remove the finish inside the tuner holes, since it would otherwise cause issues. I check the assembly tolerances pretty carefully and sand the inside of the holes if it is too tight. Unfortunately a lot of people will just force things together without really thinking, so Warmoth is probably making an allowance for that.
Appreciate this question, I'm planning to use the same tuners and had just planned to use the Gotoh/Grover option that has worked for all my other Gotoh tuners. Measure twice, cut once!
I used the Gotoh/Grover ream with a set "magnum lock trad" Gotoh tuners I bought from StewMac and they fit perfectly.

Yep, this. Gotoh Magnum locks are my favorite tuners, and they work perfectly with Warmoth's Gotoh rout. I've done it many times.
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