I built a new 40x60 shed in 2008 and considered many of the same questions. The first I will ask is why you believe you need "fresh service from the transformer" -- this will result in a second meter, and in many places that is billed not only as a second service (~$20-40/month) but also at commercial rates. I ended up placing proper PVC conduit to the service entrance at my home and connecting to a second set of lugs on the existing meter, despite the fact my transformer sits only 25 ft from the shed (vs. the house's 70 ft or so).
The "best type" of panel is one that meets your needs at the best price point. My own recommendation is to match the panels you already have in your home, so that you have one less difference in type of equipment. If it doesn't matter to you, then use your preference. Many different people have their own preferences - my personal preference is QO for brand new work for quality reasons, but my home and garage use CH panels and breakers because that's what was in the house first.
I don't recall what my total costs were for the wiring, but it will depend on what you need -- do you need a welder outlet? Any large pieces of equipment like a compressor or specialized woodworking equipment? What lighting are you using? All of these factors will change your costs.