Wheels, hubs, or rotors!!! what's the best for me to do

Hi All

Here's the situation. I've got a vintage (99ish) Ginat Box One. It's in excellent condition and has been garaged for the last 7 or 8 years. I replaced the original Formula cable discs with a set of Magura Louise Discs.

Now the problem I have is that the formulas used 4 bolt discs and the Muguras use 6 bolt so the original hubs on the Giant will not take the 6 bolts. I'm looking to get the bike back in working order as a back up or even to sell it on. What's the best thing, and the cheapest, for me to do.

Should I get new hubs and have them built onto the rims that I currently have (the rims are pretty much brand new), do I get a whole new set of wheels with 6 hole hubs, do I try to get hold of some 4 bolt rotors which will work woth the maguras, do I admit defeat and use the Giant for spares, or do I do something completely different.

Any advice would be greatly appreciated as I'm not very technically minded.

cheers in advance