Bugman you're killing me - old PW been the "truck of my dreams" for years. It's also on my splash page at boulier.com.
http://www.hotrodscustomstuff.com/projects/1957-dodge-power-wagon-truck.htmlI've owned my 1971 F100 since 1982 and have 496,000 documented miles and on first only engine/trans rebuild back in 1995.



But if you're looking for a good utility, general use 4x4 you can almost forget a WM300 (like posted above, civilian models built 1946-1968 almost unchanged). Two reasons: Costs have skyrocketed (a junker will run 3-10K depending); a fully restored or even GOOD shape one will go 15-30K again depending on running condition etc. There are a lot of them out there any many suppliers for parts - again since it was basically the exact same truck with only turn-signals, mirrors and such changing. Original bed's are rare though, you'll see a lot of flat-beds and custom beds on the ones you do see. Second reason is the later 251 6-cyl engine. Expect LOW speed for a stock restoration, maybe 60mph max (again depending on gearing and such) and not a cruising speed for sure. If you get a custom or build one - expect to pay a lot of money and spend time if DIY. If you're a Dodge fan, the D200/D300s are great. The 318 is an engine that runs forever!
The vintage trucks, chevy, GM, ford etc (for me anything pre 1973 and smog free) are getting good prices for good restorations and I follow them closely, they fluctuate as much as triples do in $$$ range. Bronco's and Blazers demand high prices in Colorado but not as much in urban area's. They command a higher price than a restored 1/2 of 3/4 truck and any 4X4's will command even more - you might not NEED 4x4 anyway depending on your use.
My old F100 is getting tired for sure and I'm tired of patching rust and it's been totaled three times, eventually I'm going to replace it. After 30 years and a LOT of miles it's never left me stranded. I carry extra hoses, a single belt, alternator etc - all things you can fix on the road. Carburetors have become expensive though, I posted stuff about that a while back and Dave had some comments, but you can expect 200-400 bucks on one, even rebuilds and take a gamble on the quality of the core they rebuilt. Going to injection is a better way - but you loose some of the road-side fix ability.
The thought of something new is absurd to me but something 5 years old is possible - maybe. Problem is you can't work on much of any of the new trucks. You can keep you're old one going cheap but at the cost of driving an old truck. And if it's a restored truck you don't want the sand and gravel company dumping rocks into it. Me, I want a truck that's utilitarian and I can work on and won't cost a fortune - that's the rub ain't it? If you're not BRAND-Centric you have more options open to you.