I used to use the DR6/DR9 combo as I felt it was a touch better than my friend's DR5/DR8.
But, you definitely can't go wrong with the DR5 (at it's current going rate) as it is still a good preamp as compared to today's top preamps - not as transparent and detailed as current preamps
It also has a great onboard phono stage which I have used (in the DR6) for many many years before I got a standalone phono amp.
In fact, I still have my DR6/DR9 combo (lying around dormant) as they are - haha - that much hard to let go