nanoDLP

hello ,

i bought two direct shield both failed me and one of my shield burn out my pi , so i deiced to get arduino mega and ramps 1.4 
but i cant find no where how to set up things ( wires , nextion , best arduino for the job )  so if anyone could help me by
telling me what is the best the best arduino and ramps to buy and how to wire things up especially the nextion touch screen i would be so happy
note i am using lcd + led driver

thanks