i) what items you would probably want to sew.
-A leather welding apron followed up with patching over the holes in my welding gloves for starters. I can fantsize about making all kinds of leather stuff.
ii) what size of thread you want / need to sew those items.
-This is a question I wish I had known to ask myself way before I ventured down the path of leather sewing all together. Right now I have kevlar thread in size 346. WOW right! Now I know. When I bought this, I had no idea of needle sizes and weather or not a machine could hold a given needle size. I just looked at the thread next to a couple pieces of 1" leather straps ontop of the 3 oz. suede I planned on using for my apron and thought to myself that it looked awesome. That was what I started hand stitching with. Now though, hindsight is 20/20 right, thread size 138 or maybe 207.
iii) what style of machine is best suited to your projects, flatbed or cylinder bed. For someone starting out I would recommend a cylinder bed with a flat top attachment.
-All the videos I have watched on youtube makes me lean towards a flatbed, but my gut says cylinder arm. I cant get out of my head that it is only a matter of time before my wife wants me to replicate a louis vitton purse for her or I think I want to make me a leather backpack.
iv) buy a brand name if your budget allows.
I would love to find a used machine for around $1,000.00 to $1,500.00 on one of the local classiifeds. I been looking for a few weeks now and they are pretty expensive for being used. I am a little surprised at what the sellers are asking. some are asking the same as new price. As far a name brand goes, if I buy a new machine which is stillan option, I may be buying one of the following: Cobra20, Cobra 26, the techsew 2750 or the techsew 1660.