Well most testing locations don't have arrangments for CBT any more, because of the new iBT test.For more info check the TOEFL Bulliten available online from ETS website for the *CBT* version and not the iBT version.You can check from there if they are still offering CBT at your testing location.
In general, most people like myself preferred taking the CBT because apparently it seems more easy, but its not difficult getting a good score in iBT as well.I can say that for sure, after going through both of the testing experiences and scoring 267/300 (CBT) and 111/120(iBT).
Cheers,
Cogbot