IAD tends to be very junior in the lower 1/3 of the CRJ list. I think we had something in the vicinity of 12 new hire F/Os bid out in the most recent bid, so they'll need that many plus a few more to backfill by May.
Did you mean KMHT? No direct service to IAD anymore, you'll either need to go to DCA and take the metro over (about $6) or two hop it. Logan would be a better option (usually no issues on JB, United can be a huge PITA) but I know parking is way more expensive.
If I were you, EWR ERJ would be my preference, maybe even CLE. Good luck!