I have a DVR 501 - had it for a LOOOONG time. Need to upgrade! However I get Dish for the International channels only so no HD. Can you tell me which receiver would be suitable for me - I was thinking of Dish 625 but maybe I should get a 612 just in case the Int channels get HD. Also - the 501 is one tuner. If I get a 2 tuner DVR - woudl I need to add another line coming from the Satellite. Also - if I do eventually go HD - would I need to change my Satellite set up (I have a Dish 500 outside). Thanks in advance for your help!