ok so u need to determine what inputs are available on the lcd tv, and then determine if its possible to use the jamma adapter u purchased with the lcd tv (it looks like u need a tv or monitor which can accept 15pin VGA input). im guessing your lcd tv doesnt support VGA input then?
in which case u are left with the option of either using some device inbetween the jamma adapter and your lcd tv to convert 15pin vga to rgb scart (assuming your lcd tv supports rgb scart, i assume it does?) .. well, im not sure i would recommend going down this road anyway
so another option: replace the lcd tv with anything you like, as long as it supports vga 15pin input
ps. regarding mame, i recommend using mameuifx which is targeted towards arcade cab/table users. it's great! (no frontend necesssary)