Looking to ID these tank cars

[Philip H]

So a freind who posts all sorts of stuff on Flickr (http://www.flickr.com/photos/lambj/sets/72157624101385733/) shot the above recently.  can anyone tell me what model would most closely approximate these in N scale?  I was thinking the Atlas 20K cars, but not sure . . .

[Hyperion]

The tenders are all a little different, ranging from about 19K gal to about 23K gal.  The Atlas car, at about 21K gal kinda straddles the line between them all, so it'd be a good fit if you were happy with a foobie, which I would be.

I suppose if you really wanted to, you could cut a couple scale feet out of one and add it to another, to get both a longer car and a shorter car.