Converting Tamiya's 911GT2 street

Seems like Tamiya's 911GT2 Club Sport is a 1998 version... what would it take to convert it to a 2001 version?

The GT2 kit you are refering to is a totally different car. The new GT2 was derived from the 993.

The tamiya 911 GT2 road version is two models of porsche in one. The 1998 Porsche 911 GT2 (993) has different wheels, and no roll cage compared to tamiyas kitset. But the 1995 Porsche 911 RS clubsport (993) has the same wheels as in the kitset, and a roll cage but no turbos and was released in 1995
So tamiya has basically released the rs clubsport with turbos, and called it the Porsche 911 GT2 Road Version Clubsport.

I think that both the 993 derived GT2 and the 996 derived GT2 could be order with or with out a cage. A friend's wife has one of each, and they are both caged.

If you are going to get the Tamiya kit of the street version , I just remind you that the wheel´s set aren´t correct. The standard wheels were +/- the ones seen on the (964) 3.8 Turbo s .,but wider, with deeper rims. and the center painted shiny medium grey metallic.

The current 911 GT2 (996) it´s completely a different story.