I think you'll be fine with the L. I wear a 6/8 in pants and I have one pair of beach pants in a M and one in a L and they both fit, although I like the fit of the L much better.
Are the larges loose, or still fitted? I'd like them to be fitted but not super tight. Oh, and just for a frame of reference, do you mind me asking what waist size you wear in sized jeans (like 27, 28 etc.?)? I'm most worried about how low/tight they are on the waist.
TIA!
__________________
Forget, forgive, conclude, and be agreed. - Shakespeare