I would definitely go electric. No stiff hoses in the way, no worries
about lubricating the tool, no noisy compressor, nothing.

A small motor spinning happily away using much less electricity than a
10 - 15 amp rated compressor that won't power a pneumatic sander
correctly.

I have a Sioux close angle drill that I use as a sander that I bought
from Klingspor with a goodie package of paper some years back. It has
been a real workhorse and I love the lack of noisy compressor motors
while working.

Even with a large compressor, you will keep it busy with a pneumatic
sander or grinder. These things are essentially a blow by turbine
that generate no torque of consequence, just whiz around very quickly
to build momentum to do the work.

Even if you still need to buy the compressor for other things, on the
sander, go electric.

Robert