for the paint you can usually get it at a auto parts dealer like napa. if they have a good selection of body work supplies in front then there is a good chance they have a paint mixing bank. there is a place where i live that supplies some of the smaller shops with paint. as far as brand i would go with ppg. i have heard bad stuff about dupont, never really used it. there are a bunch of others that are good but you are kinda limited to what you can get at the parts store. grind welds down with a 3" 3m weld grinding wheel
http://www.levineautoparts.com/3mgreencor38.html. and finish with a 36 disc on a grinder. or use a 36 flap disc on a 4 1/2" electric grind er for both operations. if you have any other questions let me know.