algyteam.com has flags & poles, batons, knives, etc. Check them out. I know they have all that in their catalogue, I'll hafta recheck the website to see if it's on there too but they have all that for sure. I was on flagline for 2 yrs (auditioned for 4 before I made it finally) but all I remember is the flagpole I think was 6 ft. long. I'm 5'8" & it was a bit taller than me. Now, when you first start, I suggest wrapping your palms & in between your thumbs & forefingers with sports tape or use gloves, tape is best because w/o it, you'll get blisters starting out & the tape will help protect your hands til you toughen up so-to-speak then you can do w/o the tape after a few days or couple of wks. I'd start out w/plastic poles, they're light & easier to twirl & toss but beware of any good breeze or wind blowing coz it'll get ya. Heavier poles are generally used w/bigger flags. I'd say an average flag would be 3-4 ft across, if anyone knows different, feel free to correct me.
Our poles had velcro on them where the flag went to attach it to the pole so it wouldn't slip--great idea to use. It's good to use the self adheasive type coz it's just peel & stick. Hope this bit of info helps.