All accounts with a DVR (not 501/508, those are PVRs) will have a $6 DVR fee, even if just one DVR. So doesn't matter how your account is structured, you have a 510 or higher and you will pay a separate $6 fee. The one exception will be 922 accounts which will be a $10 DVR fee.
The primary receiver will be based on the following hierarchy
1. 922 (slingloaded hd duo dvr) $17
2. 622 (hd duo dvr, to include 622, 622HZ, 722, 722k) $17
3. 522 (duo dvr, to include 625) $14
4. 222 (duo rec, to include 222k, 322) $14
5. 612 (hd solo dvr) $10
6. 512 (solo dvr, not yet released) $10
7. 211 (solo rec, to include 301, 311, 3900, etc) $7
8. 501 (PVRs, to include 508) $7
The receiver that is highest in the list will be the primary receiver. The more feature-rich receivers will have the highest fee.