Right back (and LB as
mykolenko is dreadful for our buildup) is where I would start, it would improve the attacking balance of the team and free up JOB to go to CB.
They have the benefit of being cheaper positions which we're more likely to be able to fill in January, a striker moving in January is doing so because something has gone wrong or obscene amounts of money are being thrown around.
Of course if a good striker is available on loan we should go for it, it is a glaring issue I just think we're very unlikely to do anything other than compound our problems buying a new one in Jan.