I am intending to turn my 1950's JC Higgins into a pack mule. Since I'm not necessarily trying to keep it strictly vintage, is this better discussed here or in the Mechanics board?

Will I need to upgrade my wheels or can I just respoke them? Cost?
What racks and other load carrying gear do I need? Anything detatchable? I will carry a heavy tool kit and lunchbox at times, among other things. I would love to carry a couple hundred pounds of swag as well as me being a clydesdale.

What's a pack mule?

If it's a loaded tourer destined to do hundreds and thousands of kms with gear, I'd rethink the plan. Get a light, strong purpose made frame to start so you won't need to break the bank to add braze ons for all the accoutrements you'll need.

If it's a townie beer/grocery/trailer hauler then spend whatever you want but it should be done cheaply - again the frame really doesn't merit the investment. Wheels? Yes, definitely. Gotta pic of said Higgins mule?

This is all worth 2 cents.

Do it. I'm close to finishing the same. A 1957 with 3 speed IGH, 3X rear derailleur, 2X chain ring. Going with older Weinmann 700C alloy rims 36 hole, 3 cross. Hope to get some touring in with it.

Lectraplayer, you can buy new "cruiser wheels" that are cheap and reliable and probably lighter than your original ones. Id just do that unless you want something fancy like a multigear hub. Them keep your original wheels in case you ever want to put the old cruiser back in factory trim.

If you want to carry a lot of crap you really can't beat the wire mesh pannier baskets made by Wald. They weigh a quarter ton and look like hell on wheels but no one ever complained about carrying capacity. If you don't have a luggage rack already there is a version that bolts directly to the frame. For more elegant options there are reproduction fifties style racks to which you can attach separate baskets. Most likely your local bike shop has all these things in stock or can get them on short notice.