The most desirable is the one you want lol. as a package Alan maybe right but there are that many variants. There are VXR & Zetec turbo's, V8's, Zetec Even a Nissan & Toyota engine variants out there. A lot of 2B owners may have upgraded the front suspension. and then you start again with the GBS zero can depend on the pockets and knowledge at build stage.
If the budget stretches i would personally go down the Zero route as there is a massive difference. However having had a 2B sliding pillar they are all fun cars to drive and tinker with.