I'm a little out of my element when it comes to A/C hoses, but I was more than a little intrigued by a line of A/C hose and reusable fittings from XRP that I discovered when I was doing the research for my replacement oil cooler lines. The idea of reusable fittings that don't require crimping is one I can get behind as a DIYer.
Here is a sample of what they carry.
I'm going to guess that to transition from the MB fittings to "standard" fittings would still take the services of an AC shop, but making up an adapter rather than making up lines would make future maintenance easy with no special tools required.
For those interested, these fittings are on page 65 of their current catalog which is available as a .pdf file -
XRP Catalog