Hi Matt,
I don't remember all the details on Skip's kit, but I believe the engines were fairly small... maybe 4 .40's or less.
There's another scratch-built C-130 in the Julyy 1999 issue of RC Modeler, by Joe Grable, with a lot of photos. His was done is the Coast Guard paint scheme, and used 4 Saito .91 engines.
There's also a kit at
http://www.ucrcs.com/QualityCatalog.htm and you probably are aware of the one on Jet Hangar Hobbies' site, at
http://www.jethangar.com/
I found a page for you called the "C-130 Headquarters", with lots of photos and info on the actual aircraft, at
http://www.spectrumwd.com/c130/
Hope this helps a little.