I just bought an Onkyo 605. It has 2 HDMI inputs and 1 HDMI output.
Picture the 605 as an intermediate step between your inputs (sat/cable, DVD, etc), and outputs (TV, surround speakers).
HDMI
The 605 can receive HDMI input from Dish DVR and any 1 other source (BluRay, HDDVD, PS3, etc), and output both to your Samsung TV. I'm assuming your TV has HDMI input?
Upconverting of other signals
The 605 will also upconvert composite, S-Video, and component to HDMI.
The 605 drives 7.1 surround, but this really depends on your source format.
Not sure why you would need a HDMI/DVI adapter. Which component that you currently own has DVI?
Hope this helps...