http://www.dnstoys.com haver all the figures your after on there site and not to bad on the price.
EDIT: Double Checked So far he has the Following
Transformers 6" Titanium Cheetor & The Fallen $31 The pair
Transformers 6" Titanium Starscream & Optimus (RID) $29 the pair
Transformers 6" Titanium Rodimus & Soundwave $29.00 the pair
Transformers 6" Titanium Optimus Primal & Scourge $29.00 the pair
Transformers 6" Titanium Jetfire & Thundercracker $29.00 the pair
I think Digital Toys may have them. I have them available Over here in Argos Stores but the uk currency when working this out would mean $60 + postage to make up the costs in any case for me picking them up due to the transfer rate