I think you can pretty much wear any brand/style of sweaters you want over a dress shirt. At least for me, the key is 1) fit and quality relative to price for the sweaters and 2) make sure the shirts are fitted (This will help with the silhouette). Personally, I wear alot of v-necks and qtr/half zip sweaters in lambswool, merino wool, and cashmere. They tend to hold their shape the best and go well with shirt sleeves rolled up. I also have a few cotton sweaters but I tend to stay from them b/c of the shape issue. As for brands, I started with BR but have gradually moved up and will no longer buy BR (also their quality has gone down significantly). I found that JCrew makes a decent merino wool v-neck if you get it on sale. Polo makes some decent ones. I've also recently purchase some scottish cashmere from Off-Saks that I really like. Some day I'd like to buy some Loro Piana sweaters but that may be a pipe dream! Finally, I posted a question on how to roll shirt sleeves with a sweater
here if you're interested on how to do it properly.
