Well folks it seems that I'm going to have to eat a little crow on this one. After checking the price lists for Freestyle and The Bigcameraworkshop the size for the 122 film offered by Ilford is indeed the correct size 91.5 mm. However, the 9 cm/90 mm shown is basically the same size but is, for the most part, less expensive than the 122 size (91.5 mm) offered. Anyway, you make the call on this one depending on your preference.
MPEX's prices for the 122 HP5 and 9cm FP4 are the same.
Oh wow, just checked. I like Freestyles prices on the 9cm FP4!