IMO that is old tech. It may be an option for 2.4L base models, but the 2.0 GXP will do more with less once the ECM is fully cracked. Crack that ECM!!
A turbo V6 is an intriguing option. From what I've read here is that people will wait for a modern gen V6 from GM that is capable of serious HP, then use that as a base mod for the solstice. It may be a little while, but with new CAFE it will be coming.
kw......