Rapha, nice but a bit pricey?

I'm seriously considering splashing the cash on some assos bib tights. I'm Just over 6ft and around 31" waist, with a mega skinny ass. Would medium suffice? I've gone small on non-bib shorts before to get the fit, but I guess I need length of strap / leg too now.

Also... Rapha deep winter jersey - worth the £160? They look beautiful

I have it, really good jersey. In winter I wear it over a full sleeve base layer and its perfect. Coupled with a buff and full finger gloves and thats the top half sorted.