Theres also the hrap 2 SE which comes with saimitsu instead of sanwa parts. I'm not sure if theres also a hrap 3 SE version.
I wanted the hrap 2 SA but couldn't find it, so I just got a hrap 2 off ebay and got sanwa buttons seperately. As long as you have the proper tools switching the buttons is easy.
The stock hori buttons(on non SA/SE versions) aren't that good and should be replaced if you get one. I suggest sanwa, but saimitsu isn't bad.