HDLimited

I'm getting into sewing patches on motorcycle vests. Got a consew 206rb & consew 29 patcher. I've read this site for hours and got lots of great info. I know I should use #69 thread and have seen recommendations on BNT. Should I use bonded nylon thread or bonded polyester? There are more colors available in nylon but these vests spend lots of time outdoors in the sun. Thanks in advance for your help!