Congratulations on your plans to relocate next year! I too have relocated to Colorado (in fact my husband is from NJ) and understand that it can be a stressful experience especially when you are purchasing a home in an area that you are less familiar with. So my hat is off to you for getting out there and asking questions.
As far as your question regarding purchasing a home in the less than 100k range, I can only answer to the Denver Metro market as that is where I do business.
We definitely have inventory that is priced under 100k in different parts of Denver, Aurora and other surrounding neighborhoods. A high percentage of the inventory that is priced below 100k is distressed (as in short sales or bank owned properties). With this in mind, I do think that it is very possible for you to find something however you may want to think about what type of work you are willing to do as far as updating or renovating whatever home you may purchase.
As for neighborhoods, ever city has the "not so good ones" and I would highly recommend just looking at each county's website and getting a better idea of crime rates (proximity to homes of interest, schools, etc.).
If you get swayed by all the amazing sites and things to do in Denver, please feel free to contact me at (720) 988-5952.