do y'all recommend 10' or 8'?
I'm wondering if the 10's are stable enough?

8'

I have had 8's on my last three boats, my new one will have them as well, the 10's just stick up to tall for my liking and 8's fit my style of fishing just fine.

Try going under the Athens Lake bridge where the road crosses. I'm glad I had 8's..they cleared by two inches before I was able to lower them.
8's are just easier to handle.

Installed 2 10' poles on our boat (about a month ago) that recently had 1 8' pole. Loving the double over the single. The 10' poles are very tall. 10' poles require braced mounting brackets which makes them very stable. There were times with the 8' pole that I wished it went deeper. - so basically I am saying that unless you have height restriction go with the taller poles.