I think it might be wise to go for something a little more powerful than 30 or 40wpc. Perhaps that's enough for you though, I'm not sure how loud you listen and what your room is like...
Anyway, the amp section of the NAD C-328
measures quite nicely (the DAC doesn't unfortunately). Based on these measurements an Amir's of the 7050, it seems that NAD's amplifier sections perform better than their DAC sections.
I can't find measurements of the other two units but it's likely they are also decent performers. The D3045 has more power, which might come in handy.
Interesting story about your retirement too. Hope you're enjoying life over there