custody in missouri

I am seeking to modify my current child custody. My ex-husband and I have joint legal/physical custody, he has primary residence. Since 1996, my children have been physically & emotionally abused by their father and step-mother. Their step-mother has attempted four times to have someone MURDER me, but because she didn't say how much, or offer goods or services in exchange, the police say they can't prosecute her. I have two of the letters she sent to one man asking him to "permanently remove me from human living". My ex has consistantly refused my visits, he moved to Florida without prior notice in 1997, for 6 months. I was told by law enforcement and legal professional that I needed to hire an attorney and go to civil court. His wife told my children I didn't love them because I refuse to move to the town they live, everything and anything to try and turn them against me, primarily because I couldn't afford my full child support every month. My girls are now 15 and 13, and do not want to live with their dad. I live in Kansas so I can't get Legal Services from KS for a Missouri case, and MO Legal Services does not handle modification cases. I have talked to attorneys, but they all want $3000-$4000 for a retainer. That is about half my yearly income. I wrote my own motion to modify and filed it, but now I am not sure how to get police reports, social service records or how to make my ex comply with requests for income statements. He owns his own auto body business and claims he is not making any money. He has bought cars from auctions and had them put in my children's names, to avoid having a car dealer's license. But I don't know how to get the proof for court. This case will be heard on the 29th of November, 2000, in Vernon County, Missouri. I NEED HELP! FAST