There are 3 Elint ops on an RJ. Three!
Cram on enough to do the full R1 role and the RJ would be more than merely crowded.
And even now, the RJ isn't that much more spacious (and has even fewer windows.......)
As to unmanned - a UAV can do Elint and Comint in the same way that a U-2 can. What it can't do is RJ or R1 style Sigint missions.