I'll make it all inclusive, as much as I can.
Nitrous: 3"
Flux: 4"
Burner: 3.6" using a 1.5" stroke shock (stock), 4" using a Turner custom 1.75" Vanilla RC and the shorter X rockers, or 4" using the 1.5" with XR rockers (also known as Romic rockers)
XCE: 4" using the 1.75 shock and X rocker or 4" using the 1.5" Romic and XR rockers.
5 Spot: a bit over 5" travel in the rear as the rocker was slightly lengthened for clearance.
5 Pack: a Six Pack/RFX main triangle mated to a lighter 5 Spot rear end with a 5" Spot rocker
6 Pack/RFX: 6" travel bike, heavier duty front end and rear end.
A six spot was just something mentioned by someone as a 5 spot with an RFX/Six pack rocker, which I doubt will ever happen in production.
The old RFX also had different rockers, going from 5" to two versions of the 6". One for a taller bb, one for a shorter one.