cfreidma Welcome to the list of 450 owners! You got it at a steal!

How many miles are on it? Incidentally, I bought both of my 450s while I was living in Boulder, CO.
If the car is already titled in another state, it will not be a problem to get it titled for Colorado. Be certain that if the car is titled in another state that you get the title transferred to you immediately. Once that arrives, take it, your driver's license and vehicle info to the tax collector's office to get your title and plates. Usually they have to manually force your VIN into the system but all states have to do this with grey market vehicles.
Big Panda's post is his opinion. Of course once you weed out the opinion, you do get some fact. Most importantly is Penske has forbidden their Smart dealerships to work on the 450 and from ordering parts for the 450. Lots of political and historical reasons here that I can bore you with some other time.
As for service in your area you're in luck.

Paul Myers is the services manager at Smart Center Denver (actually in Englewood on S Broadway) is an amazing individual. He will work on your 450. He is a great guy and very honest. He can even get you a nice set of winter tires when the time comes.

If there is something he can NOT fix, you will find the site
Evilution - Smart Car Encyclopaedia very helpful. Just be sure to uncheck the boxes for the ForFour and Roadster before browsing Evilution.
Parts are a little tricky however they seem to be getting easier to source. I - and many other 450 owners on this forum - have had success with getting parts from G&K,
shop.flyingtiger.ca ,
Parts4Smarts North America - Smart Car Parts Distributor: Home in Canada. For US based shops,
SmartCar Parts LLC Based in U.S., ship WorldWide: interior & exterior parts, accessories & add-ons for the Smart Car and
Smart Madness - smart car parts and accessories carry 450 parts (I recommend you get the California Pop Top from SmartMadness). Those should help get you started.
In the forums, you will find a LOT of info about operating and sourcing parts for the 450s. I've started a 451 parts that fit the 450 thread here as well. That thread is a list of parts that you CAN order from the Smart Center that will work in your car. These parts are "technically" for the 451 but I have them fitted to both of my 450s and they work great. You can find that thread at
451 Parts that fit the 450
Glad you found a car that you like.