Just to inform all of you in advance as Ferrari F1 on Spa is concerned - the remodelled Spec 2.0 suspension is now independent and Ferrari F1 cars have a very low Ride Height by default.
In order to have a non-bumpy ride on Spa and to avoid massive planking on both Ardillon and Blachimont you will need to alter Ride Height massively.
In the same time, default values for Formula GT vehicles suspension are decent for out-of-the-box Spa pleasure.
To answer you dilemma Xun, 2007 is maybe a bit faster but also slightly demanding to drive. I would go for 2007 myself, but wait untill DLC is released to see what new Seasonals will PD introduce - which they probably will - in order to avoid buying the wrong one maybe