summer tuxedo buying used questions

I’m looking to get a tuxedo for a wedding this summer. I’m toying around with the idea of getting one of Poshmark. How do the pants work I’m confused. Should I just do jacket and wear nice black pants on bottom? Any advice for a cheap lad like me? Any brands I should look into? Is Hugo Boss sizes wacky?
42 R jacket
34x32 pants

Im 6’ 190lbs (182.88 cm 86.18 KG)