SlickRick, you're right in thinking that your friend will need to run a high psi. That's why I'm going against the general consensus here and suggesting against Worksman wheels. While the Worksman wheelsets are super beefy, the bead-hook on the primitive rim is only rated for something like 50psi. High-PSI situations will lead to the tire blowing off the rim. That ain't coming from Bike808; that's coming from Worksman themselves (although I do own some Worksman wheels, and I believe it.) Beyond that, I've found that steel rims tend to come out of true more easily than good-quality aluminum hoops. Plus, I see that you've already got the rolling stock figured out, minus tires. So, I'll focus on those.
I'm going to suggest Schwalbe Fat Franks, which are rated to 60psi but I pump mine up to 65psi without problems. Only had 1 flat, ever, in about 3 years of almost daily riding on the same set- nail popped thru the tread. The 26x2.35" size fits most cruiser frames, and will work OK with your 1.5" rims. (Schwalbe also makes the Big Apple, which is a bit cheaper, and says 55psi max on the sidewall.)
I weigh 250lbs, which may not be very heavy in the world of fat guys, but it's pretty dang heavy in the cycling world. I've had good success running balloon tires at/around max psi on Sun MTX-33 rims, laced 36/3x. That's the way I've been skinning this cat, but there are probably other methods. But if you want a durable, high-volume, high-PSI, fast-rolling cruiser tire, you won't likely do better than the Fat Franks.
