portable

I want to get a compressor so that I don't have to worry about where to get my tanks filled. I've already narrowed down the options and likely looking for a used Bauer Junior II or a new L&W 100. What I am trying to figure out is whether to just get a lower-maintenance and lower running cost...

I live about 200 miles from a refilling station and I would like to buy a used, but still fully functioning, compressor to fill my own tanks. I live in West Texas. If anyone has had any luck with more affordable compressors and modifying them to produce breathable air please let me know.