dont live in denver but i was born there!
if you can find a place that offers month to month thats always a bonus. contracts can give you a discount based on how long u sign for. which is pretty normal biz practice in any biz taht offers those types of set ups.
contract only....can be an iffy situation....esp if its expensive.
as far as style goes....well just find something, anything really, that you are comfortable and excited about.
as you will come to learn, the style is not as much a big deal as to whether or not that school is going to help you advance towards your goals.
i like to look at 'styles' in terms of : stand up and grappling and then a mixture. want to punch and kick and learn some take downs and throws, chinese martial art is a great fix, unless there is cross training there you likely wont see much ground work, which is fine. looking to focus on throws/takedowns and submissions try out some jiujitsu / judo / wrestling etc...
other than that, taste test as many places as you can before you make a call. UNLESS you just feel the right vibe at a place and you want to train there. then jump right in.
the great thing with starting martial arts is finding a fit for yourself, if you are into learning new things and are open minded, you cant really go wrong.
the almighty $$$dolla dolla bill$$$ will be a factor in a lot of schools. but just look around at the local market to see if things are being competative with rates....
For whoso comes amongst many shall one day find that no one man is by so far the mightiest of all.