Having raced both classes over for over 20 years i would say:
Electric and IC are equally as good.
The IC cars are heavier and generally more stable and easier to drive. The downside is you need a friend to tune your engine before the race and refuel it in the finals.
Also learning to tune your engine takes time and patience and can be frustrating (A lesson learnt from experience).
The electric cars are just as fast nowdays and with LIPO and Brusheless require very little maintenance. And you can go racing on your own without having to arrange for a pitman (this is why i switched back to electric).
I have also found that i tend to wear out more tyres on my 1/10th buggy than my 1/8th rallcross car.
The other thing i would look at is what classes your local clubs race as that is probably the best way to choose.
Whatever you choose i hope you enjoy racing as much as i do.
PS i agree with Adam most newcomers at our club start with a B4.
www.trcmcc.co.uk