Nicu,
The FCC allows a condo owner to install a dish of no more than 30" without any approval of the homeowners association. The fact that you have a dish already up complicates things. It could very well be that after you get the first dish up, that you may not be able to put up any more if your association doesn't allow for it.
Any chance that a single dish solution would get you all the channels that you need? The FCC regulations were written prior to when the satellite TV providers started using multiple orbital slots which may require multiple dishes.
I had this same problem until our entire building was wired for DirecTv about 3 years ago. Now the problem is that we don't get any of the HD stuff, and the cable company is sueing the satellite TV installed for using the last run of cable for the DirecTv feed.
Let us know how this turns out.
Good luck,
Robert