If the reason you want the freedom to choose a technical solution is because you want to use a really good technical solution, it might be a good idea to find a consulting company to work for that takes pride in their tools and practices. Ones that come to mind include Pivotal Labs, Viget Labs, Intridea, and here in Boulder, Quick Left.

If working remotely (i. e. from home or while traveling) is a big part of your reason for contracting, I suggest Intridea, where telecommuting is common and not limited to people at the bottom of the hierarchy. http://intridea.com/careers