I have a 3hp twin cylinder direct drive with a 100litre tank, it struggles with some tools and don't think I could use it with HVLP. The 13amp fuse blows sometimes on startup in cold weather and I should definitely have got one with a bigger tank, it all comes down to cost and space and the larger compressors might want three phase.
As to welders I have a 150amp Butters gas mig which runs on a standard 13amp socket and I have found it more than adequate for any of the welding on my Vitesse, understand than some cheaper welders struggle at lower settings.
Get yourself a very good quality reactive welding helmet and practice practice practice, also some very informative tube video's.
All the best for your restoration.
Paul.