Can BJ Official Cab be booked in advance ?

Here are the contact numbers of its call center: 96106, 96103, 96109. You'd better contact them at least 4 hours ahead. However, I'm afraid their staff cannot speak English.

In the case, you may try to drop a mail to bookingtravelchinaguide.com. I know they provide professional car rental service with drivers and you can book a suitable vehicle from them in advance too.