While it IS possible to use other keyword tools with DWS, I personally prefer TLKT because I know the data is always fresh. I've looked recently at other keyword tools like Market Samurai, and I just can't find any that cut the mustard.
DWS needs phrase match competing pages and fairly fresh data to be able to give you the most accurate estimates of how long it will take and how much it will cost for you to get your website ranked and generate traffic.
Market Samurai often serves up data from it's database history, when it can't pull the data fresh for what ever reason, but doesn't tell you when it's pulled it fresh and when it's history.
More importantly uses Bing data for traffic estimation and competing pages which I haven't been able to correlate consistently so that we can use that data in our algorithms. (source: http://www.noblesamurai.com/blog/technical-updates/were-back-2888/) These are two of the most important pieces of data used to calculate your cost to rank and time to rank.
That said, if you are still ok with using another keyword tool's data, there is the ability to be able to import anything into DWS though a custom template.