I am trying to compare Umbraco with Orchard, and though I could find free Orchard Skins (not many on the site) but couldn't find any for Umbraco.
And in general I looking for CMS system for my own site, what should I choose based on Professional support and ease of development (I am a .Net Developer too)
You can pretty much use any HTML template, but you would have to set it up yourself. This makes Umbraco pretty flexible. Orchard is a little like DotNetNuke with its skinning capability because you can put things inside of styled "containers".