Replacing D-link 604 w/ D-link ebr-2310 ?

you could get a wireless router for about the same price like $5 to $10 more. I think it is worth a try.

I cannot guaranty that the wireless works everywhere in you house since there are many factors like type of material the wall and floors are made of, how many wall the signal has to travel through, whereby radio frequencies will be you least problem since there are 13 channels to choose from.