The retail version probably makes the most sense for a first release as it would have had the widest availability. Pretty sure I read that a G2 version and an SDCC/Platinum Grimlock vs. set are coming too - the G2 version topped out the poll on TFW so I'd say that's almost a certainty. There's even a rumour of a Ruination set to come with redesigned parts for the differing limb configuration.