I've decided to bite the bullet and get a sewing machine, but I need some guidance. I don't picture getting into bags very often so a cylinder arm isn't needed...yet. I was looking at sailrite for a bit, but keep getting directed to Cobra. My question is can a class 20 cleanly stitch thin pieces of veg tan, say 3-4oz? And same question for the 18. Also if you have any recommendations on other models to look at please let me know. Thank you.