Front disc brakes will have to be aftermarket, never offered by GM in 1958. You can search for a complete kit (much better than piecing together the brackets, rotors, calipers, proportioning valve, hoses, etc.) like this:

Adding power booster increases cost quite a bit but is well worth it, you will be amazed at the difference in braking.

The kit I show above is the one I used, includes 2" dropped spindles which really helped get the nose out of the air, especially when used with new springs. There are other complete kits that use your spindles but the brackets will alter your track width by an inch or so.

Also be aware that most disc brake kits will require that you change wheels, your original 14" wheels will not clear the caliper (15" wheels are fine, or you can source 14" wheels that are made for disc brakes).

Note that your 58 uses same kit as 55-57 so there are plenty available in the marketplace. Shop around! One source:

http://www.lategreatchevy.com/chevy-power-front-disc-brake-kit-complete-1955-1958.html

If you are an automotive business, you will get wholesale price here:

http://www.mbmbrakeboosters.com/index.php?option=com_virtuemart&page=shop.browse&category_id=7&Itemid=6

Dave

Recommend you check out CPP:

http://www.classicperform.com/fullsize.htm

- they have nice kits and are way less costly than Eckler's, aound $600 US complete.

"Kit includes: disc brake bracket kit, rotors, loaded calipers, bearings, seals, dust caps, spindle nuts, hoses, 7", 8" or 9" booster, master cylinder and pre-bent hard line kit, and proportioning valve."

Shipping to Germany will be expensive I fear, all that cast iron (calipers, rotors, master cylinder) weighs a lot.

Dave