So a bigger part of this question is about models of round roof boxcars. I'm excluding the wagon-top, and the Seaboard cars (a Sunshine kit for one of those is coming up soon on my build list), just the genuine inset- and flush-roof styles.
I'm not fond of the Bowser cars, since I tried carving the ladders off of one a few years ago and got halfway through before I gave up. But I do have several of the Bowser kits still.
Then there's the brass ones that were ok for their time, but are lacking in detail. I believe those were the Trains inc. (?) I have one of those, which I'd rather sell than paint, but they made most of the major PRR classes and variants.
The Sunshine kits come up on eBay from time to time. They're the 10.x series, so among the earlier kits. I suspect sales of these went through the floor after the Bowser kits were announded, which could be why they come up relatively often for sale. I would build one or more of these if I thought they were relatively easy to build -- as they should be, since in my opinion the weakest point of early Sunshine kits was the roof, and these appear to have a one-piece roof based on the kit photos in the eBay offerings. It appears that Sunshine never did an X32.
So if you were me, and only needed a couple of round roof cars, whether PRR or not, which one(s) would you recommend? Modeling a secondary main line in Kansas, 1960.