Best printesr for making model kits?

[old man emu]

I have a lot of replacement parts that are either not available, or much to expensive; and improvements that I want to do to things, so I'm going to need a scanner

I'm in the same boat as you are. For what you want to do (make replacement parts for scale models) your most important tool will be a scanner. Getting a good scanner is going to be the hardest part of your journey. At the moment, the resolution of scanners at the scale sizes you are dealing with is not the best. However, with your modelling skills, you should be able to overcome quality issues.

Several companies have released desktop scanners which will handle items of the size you need. Research those. I would suggest that the Kinect scanner of XBox would be unsuitable for your needs.

You will waste a lot of time in producing the things you need through trying to learn CAD software and producing a suitable drawn object to make a print file. Save the CAD for later.

On the whole, any 3D printer on the market should suit your needs. I'd suggest that you start with a printer in the $500 range.

Old Man Emu