We end up in St. Pancras, should we stay there and what suggestions for rooms?
St. Pancras is a busy area, but it has good transport connections as most tube lines pass through either St Pancras/Kings Cross or nearby Euston Station. If you want to stay in this area I recommend Premiere Inn Euston (www.premierinn.com)which located across the street and one block away.
There is also premiere inn called King Cross/St Pancras but it is actually further away from the station.