OK my brain hurts.  I am a voice actor and need to install ISDN in my studio to even be considered for some gigs.  I honestly am not sure where to even begin. So here are the two big ones at this point:

1 what would be the best system to buy to be competitive yet not be extravagant.  I need something that is very easy to use.  I have little understanding of how all of this works so I need something that will work with as little input from me as possible

2 when I spoke with my phone rep she asked me if I needed to bundle lines...do I?

Any and all help is greatly appreciated.