A 10mm case trimmer is probably not essential. I have never trimmed 10mm brass because I have never had them stretch longer than max length. Instead, the 10mm cases get shorter over time. My rifle brass is another story.
I run with a stock G20 barrel and my RCBS carbide dies work great for resizing the infamous Glock belly. Whatever dies you go with, I suggest selecting the carbide variety. You can get by with little or no lube.