I still have my orginal DTv system, (9yrs) and added a 2nd box box 2 yrs ago. Now I would like to go Tivo so I can watch things later, but would like HD also. I'm not ready to shell out 1k for combo unit. So the question is "Do I get the HD rec and a dtv tivo for about 1/3 the price of the of a combo unit? I just wont be able to record hd correct? I'll need a complete upgrade to new sat dish anyway no matter what.