im faster with my g25 than old momo. g25 has much better statistics. and shifting with clutch gives you much better feel in engine brakings etc. if i am same situation as you now, i would buy g25 straightaway
only need caster but it isnt possible to change anymore in "normal cars" (xrt xrg fz5).. 100lock, agressive driving style and tyre pressures.. ofcourse very tight suspensions