Of course the issue here is that this outfit is on Net-a-Porter. The Helmut Lang silk-chiffon tank is not only silk, but is $320. The Sonia Rykiel tuxedo jacket is lined in silk and goes for $1,495. And the Miu Miu boots are leather and $795. Yeesh. The jeans, at least, wouldn't be too hard to find.
For those with a little cash to spend, I tried the Connie Crepe Jacket ($288) on at French Connection the other day and it looked killer. The fabric is Viscose, Acrylic and Polyester, so you don't get burned by the wool/silk issue that arises with most nicer blazers and jackets.
Otherwise, there are tons of vegan blazers to be found at Forever 21 and H&M. It's just a matter of finding one that works for you.
The shoes are the other vegan-critical part of this look. Personally, I'm thinking these Aldo Maytorena Boots ($80), which are all synthetic.
If you don't stick to the bootie look, the Olsenhaus Muse pumps ($148.50 on endless.com right now!) are a great option:
Otherwise, I'm thinking the Madden Girl Kevvin Ankle Boot ($45.59) or the Olsenhaus Sea Peep-Toe Pump ($126.50), both also available and endless.com.