Since my kids are 14 and 12 and want to come live with me, if I get a letter from them to the judge would I stand a chance in getting custody?

As children get older, the courts will accept their input more often regarding the issue of custody and where to live.  If your children want to come and live you with you, it will improve your chances of getting custody.  However....even though they accept the input, they do not have to agree with their decision or abide by it.  How much deference the judge will give to their wishes varies from judge to judge.   If you have additional basis for requesting the modification-- then you should list those as well so that the judge gets a complete picture of you as a parent, instead of the view of a parent who is manipulating his kids to get out of paying child support.  Other factors can include:  more room for the children as the get older (especially if you ex- has limited space), access to more educational resources (museums, tutors, special programs), the quality of the schools in your area, access to better medical attention, better after school activities or care, better in-home support (i.e. if you've remarried and new spouse is helpful).  This is not a complete list, but just some examples of how you can show that you are making this request on the best interests of your children.