Yes, I do have a resource and they are very helpful.
http://www.schramauto.com/ows/
Contact them by phone - ask them for internet sales (ebay/auction/etc.). Mention that you're part of this forum and that you are looking for a tranny (they specialize in like...less than 5k mile salvages of most kinds). They can get you the 4l60e, not sure about the 700R4.
I've heard of guys getting a 1-2 year old 4.8 or 5.3 with auto tranny, less than 10k miles for less than $3000 delivered to their office. You can save money on delivery by having it drop shipped to the shipping depot and picking it up in person (they can forklift it onto your truck, then you cherrypick it out of the bed).
__________________
If I've got anything up for grabs, it'll be here: 7-hole gauge cluster for a 67-72 p/u FREE (
link)
I can't check the forum daily. If I don't reply to you within 24 hours,
drop me a PM! I'm (hopefully) still alive and will reply faster to a PM.