Equisafety Aspey jacket - sizing

[now_loves_mares]

I am looking for a high-vis jacket but want a neat fit (not vain really, as I am currently wearing what can only be described as a yellow mushroom over my riding hat

, I just find baggy jackets annoying to ride in). This jacket looked like a neat shape, but I'm quite small - a size 8. There is a teen size which is 8-10 and a Small which is 10-12. There is nothing worse than jackets being too tight for riding, so just wondered if anyone had bought one and could give advice. Although skinny I'm 5'6 so I'm worried the teen one might be too short in the arms/across the back?

http://www.equisafety.com/cat/catitem.asp?pc=R01%2DASREY&d=1&s=1

 

[kal40]

IMO these are quite small sizings. I'm a curvy chic and bought my usual size in this jacket and its tight. It is a lovely jacket though. Diet in progress so I should be ok this year