sparkler/bottle tree hybred

Thanks for all the inspiration on this site. My goal this year is to learn to post pictures. I would love to share some of my creations with you all. My latest is a bottle tree with 240 2 oz bottles but it must be assemble in place and can't do that until spring. My new project is a sparkler/bottle tree with cobalt blue beads, but I don't know how to measure the holes in the beads when ordering. I love working with 16 gage wire and wrapping it on re bar. So that's my question: what size hole will accommadate 16 gage wire? I really know nothing about beads...any info will help.
Thanks Sharon