This is one of those "How long is a piece of string?" questions to which there's no simple answer.
It will depend upon the particular company supplying the units, whether they're standard stock items or made to measure, all in stock at the time of ordering, etc. You might be able to walk into a place and get everything delivered within a couple of days, or it might take several weeks. All you can do is ask about delivery times and hope that the company keeps to schedule.
