I can help with that. To my knowledge they carry a wide range that includes Zegna, but also H&S, Loro Piana, Scabal, Ariston, Smith & Woollens, to name a few. They also provide hand stitching (but not fully handstitched - I believe long seams are machined) and full canvassing options for all jackets.
However, you will not be able to finish any garment with Iris in 2 weeks. There is a long list of orders.