It's not too hard to find, and doesn't have to be expensive (especially at the end of summer... here's a nice shirt for $15 (originally 30) - I tried these on in the store and they are great (as most things from Uniqlo are). They had jackets (sport coats) too and of course there are lots of other places to get linen things - its popularity has seen a resurgence lately.
But it gives off a certain vibe that may or may not work for you... despite it being described as a casual fabric (and the fact that it wrinkles) it isn't something you can generally wear casually by today's standards. Even just a plain shirt will give you a sort of Riviera vibe, if you know what I mean, and goes better with dressier pants and shoes than with jeans etc.
If you're wearing suits and sport coats already, though, then linen is definitely something to seek out. It's great for those and in that case turns the formality down a notch.