New Customer - Simple HD DVR Install Question

Hi,

I'm in the process of switching to DirecTV from Dish and have a simple question. 

A couple years ago I attempted to switch to DirecTV but had issues with the HD DVR receiver.  Problem was I only had one line from the satellite dish and could not (because of the condo I live in) have a second line.  The installer tried to figure out a work around so I would be able to watch a show and record another at the same time.  Unfortunately he couldn't so I stayed with Dish.

I'm still living in the same condo and have the same issue with one satellite line.  So my question is, if I switch to DirecTV will I have the same issues as before?

Will I be able to watch a live show and record other programs at the same time (with only 1 satellite line into the receiver)?

Thanks in advance for any help.  As you can tell, I don't have too much technical knowledge about this stuff...