XB2 Dirt or Carpet

[008-Racer]

Hi I am thinking of getting a XB2 but need a little advise on what kit to get?

I am planning on racing at mainly Kidderminster (Low grip Astro) and Coventry (from what I remember not very high grip astro again)

Would I be better of with the Dirt kit as I should be able to make use of the extra traction this style of kit should generate?

Any advise greatly appreciated