Do lower super numbers also indicate a more insulated garment?
Working in the restaurant industry, I often am required to wear a suit where durability is important but breathability is paramount. In the middle of service there is nothing worse than running around bringing people food and starting to sweat because your jacket keeps you too warm. Is there a fabric that is a suitable compromise--both durable, but also lightweight?
Super numbers have no correlation with the weight or breathability of the fabric. Even the weight of the wool isn't necessarily an indicator of warmth or coolness since the density of the weave greatly affects such properties. Frescos are generality the lightest, worsteds are intermediate, and flannels/tweeds are the warmest.
As far as entry level fabrics for an entry level MTM garment, I would safely recommend Vitale Barbereis Canonico among the Italians for their serviceable degree of finishing and fair retail price, along with Holland & Sherry, Reid & Taylor, and select lengths from Charles Clayton. H&S and Scabal are definitely a step up, but are often sold at a premium. Lesser, Minnis, Carlo Barbera, etc. usually add substantially to the price. I don't have any experience with Wain Shiell, and have a mixed opinion of Dormeuil. Zegna and LP are generally poor values.