Choosing who to cite in debate is a challenging feat. Not only do you have to evaluate whether or not the statement you've chosen agrees with the point you are trying to make, you also have to evaluate whether or not you want to cite the place where the quote is found. This can be a long and tedious process. Although this doesn't answer all of your questions, we've created an "at a glance" chart organized by political bias so that you can quickly decide if a think tank aligns with the ideals for which you want to stand!
Next time you're stumped on whether or not a think tank aligns with your argument, check out this chart. There will always be outlying content, so don't be surprised if you find one or two pieces by these organizations that doesn't perfectly fit one of these categories. We've made made it on a gradient so that you can tell that there's a bit of wiggle room, even when it comes to politics.