A double-breasted blazer/club jacket is a sartorial classic; usually worn with chinos or grey trousers, but nowadays you can easily hook it up with a pair of red or white pants, worn out jeans or even shorts.
DB's usually look the best on guys in their 50's or 60's, but if you're a young guy that can easily pull off blazers and suits, then I recommend going for a DB.
I think the coolest spring suits are navy colored ones; it can be dressed up (silk tie, leather shoes) or down (sneakers, lose the tie or wear a knitted one), the jacket and the pants can also be worn separately.
I think Lino Ieluzzi, the owner of Milanese Al Bazar, is somebody we can all learn from; just take a look at the perfect proportions, little style quirks (gloves in breast pocket, scarf in the side pocket etc.) and the sprezzatura!
If you like the classic Italian style, this is what you should aim for.
"Style is not fashion, it's something we have inside."