Handi is the SB2, rimfire are Sportster, Versa is the offset 22lr and SB1 are Topper or Pardner.
That is the way I seperate them, many people just lump them all as Handi, I know. I can see some poor soul not knowing the difference and trying the sportster barrel on the SB2 or SB1 after throwing down close to $200 for it.
Then again, I have heard there are some 17 versa barrels but I have never seen one myself.