We have a Makita electric die grinder. Great at what it does but a very heavy and large piece of kit. If you are planning a big restoration on your bug I would seriously think about buying a biggish compressor from the outset. I wish we had. You will have access to a lot of cheaper air tools. £100 on a big electric die grinder might be better put towards a 100l compressor in the long run. You can always sell it on when you finish your restoration.
Also, a Black and Decker belt sander (£30-40) is great at dressing down welds and removing rust - probably the best tool we have bought for our restoration and gets far more use than the die grinder.
Good quality air die grinder and reasonable compressor is the way to go. I have 2 electric die grinders and not been used for several years. Always use my Dotco air grinder.................