[Roadsters] OT: Die Grinder? Recommendations?

[Daryl Smith]

Looking at buying a die grinder for head and manifold porting and cleanup.

Looking at probably a medium or heavy duty as this will be ongoing work, but
not daily, for several cars,
and with any luck for several years.

Electric? Air? (have a 5hp 60 gal air compressor)

Brand?

I like the idea of electric, and not having to worry about the air supply, but
am unsure of any other
disadvantages, or advantages of the air grinder.....????

Costs?  I looked at some small air die grinders that ranged in price from
about $40 to $180....
wasn't able to locate any electric ones to compare.

Thanks
Daryl