I know a baby Rupert IRL, goes by Roo, cute, love it.
Don't see Guy as a baby name (I know that s ridiculous all adult Guy's must've been babies at some point etc)
Gregor is ok, but same issue as Guy for me
We liked Jesse for DS, but can see where your DH is coming from
Not a big fan of Cyrus - makes me think of Miley
Bennett's ok, bit unusual, though he'll probably end up as Ben
Same with Jacob/Jake
Like Matthew a lot, again we liked it for DS but it's BIL's name so we decided not to.