FDXMens Compression Armour Base Layer Top Skin Fit Shirt + Leggings Set

Im 5ft 11 And have a waist of about 30" Does anyone have any recommendations on size? Thanks

I am 5'9 and 34 waist.should i go for medium.

How best and how often should they be cleaned?

proberly stupid question but do i need to wear boxers with these