I had a Consew 18 until recently, I really enjoyed using it. it will take 135 thread all day long 225 is asking a lot of this machine my experience is you can get it to sew with it but the stiches don't look good otherwise it can sew through anything you can put under the foot. It will do up to about 1500 stiches per minute but it would be unwise to get much over that. You can find feet on ebay though they can be expensive and welting feet are available . Bobbins and bobbin cases are pretty much the same as domestic sewing machines and are pretty cheap. it takes a 135 type needle , common walking foot needle easy to find and cheap leather needles are available. I would just sync the upper feed with the lower feed for the stitch length I was using. The needle plate has a pretty big hole in it so when you get started it can hang up on the feed dog, just something to watch out for. The needle plates are easy to find on ebay the needle bar is also available and pretty cheap . I replaced the clutch motor with a servo motor it made all the difference especially since the old clutch motor was an ancient open motor design and was pretty "grabby" there isn't much to go wrong with this machine and once I managed to get the timing down I never had to adjust the timing again. This is a commercial machine and is well built if you keep it oiled every day you won't be needing to replace any parts. This machine does not have reverse so at the end of the seam lift the foot slide the material back under the foot a bit and put in a couple of stitches or turn the goods around and put in a couple of stitches.
I would post pictures but I don't know how to on this platform.
Dave