Do you have experience with PacBio?
If it is a good idea to use PacBio depends a lot on what you want to sequence and what you want to do with the data you get. In short: you get longer reads but about 15% error per base. This means, you will have to cope with those errors, there are possibilities to do that. How much coverage you will get of you sample I cannot tell you, as I do not know what kind of sample you want to sequence. 

How much data you get out of one SMRTcell depends also on the chemistry, I think it currently is between 275 Mb and 375 Mb, depending on chemistry. They have a nice brochure you could look at.

Anyway, you probably will have to get some advice by a bioinformatician of you choice on how to design and analyse your sequencing experiment.