I am looking to put a 12" bar on a newly purchased MS170. I have been doing a lot of reading and cant seem to come across any p/n's for the proper bars and chains that would go with this saw. I already plan on ordering the 1/4 sprocket 1123 640 2007. I would like to find the p/n for the narrower 12" roller nose bar and a good chain to match this bar and sprocket for carving. Also what file will I need. Any help would be great because I am new to the artform and dont want to waste money on any unnecessary pieces.