Best linen shirts?

Both of those are good options. I like Proper Cloth but they are mainly good for “basics.” They don’t have a ton of shirt options with more of a design element to it (and I am not talking about peacocking but something more than basic solids or white with blue stripe type shirts), especially in linen.

Linen is tough to look good in. Put on a linen shirt and five minutes later you look as if you’ve been out all night drinking in dive bars. If you have to wear linen shirts, spend what it costs to get good ones. The cheap stuff looks like hell. 

Jcrew

banana, Zara especially if i'm using it only for the summer. decent quality, can wear a handful of times and lasts the entire summer with 4-5 shirts and 2-3 pants

If you're looking for quality without breaking the bank, definitely check out Club Monaco. I've had great experiences with their pieces.

Baird McNutt linen from J. Crew is solid. Never had issues with them. My wife has dresses and shirts made of it too and she loves it as well. It holds up well for linen.

Massimo Dutti has some nice linen shirts for both men and women. Sometimes I feel linen shirts shrink / lose their shape a bit somehow but in my experience Massimo Dutti shirts keep their shape well.