I need to make some painted bi-fold doors out of wood. They will be 1 1/2 to 1 3/4" deep. I would like to get some clear softwood 8/4 stock. Lumber yards in my area and Lowes & the BORG mostly carry Southern yellow pine 2X stock which is anything but clear. If I have to mail order the stock should I look for fir or some type of select pine? I have never purchased good quality softwood before and am at a loss what to look for. Hopefully whatever I use won't tend to warp too much.