The problem I have with a series set in the 25th and 26th centuries is the technology would be getting too magical, or
you would have to cook up a reason that technological advancement largely stopped in the 24th century. Some kind of general societal fall like a Federation civil war would be one possible explanation.
A Titan series would be a nice possibility, we would have Riker and Troi to anchor it to previous Trek and then new characters we've never seen before to move the show forward. At this point recasting Riker and Troi would basically be a given.
The show could start immediately following the events of Nemesis, or pick up months/years after Riker takes command.
The Titan books have good adventures, but some of its more-exotic crewmembers might be difficult to depict on the small screen.
The Titan TV series wouldn't have to have any connection to the books, the ship and characters would be fresh creations.