i like wolf secundo rests.. they can sort of mold to your shoulder and are fully adjustable.. they are a bit expensive but well worth the price

SHoulder rests can help but it has always been my opinion that they should wait until you are learning vibrato, also they make `pillows` that are not as tall as a shoulder rest but allow you some cushion- I would recommend this (becasue once you start using a shoulder rest you never stop, and not using one allows for more movement)

As for your touching the strings...you have to use the very tips of you fingers. My violin teacher was a 70 year old man with huge fingers and he could do it. Keep your fingernails very very very short. I don`t think its an instrument problem