You will need room for a walkway through the space, which should be at least 4 feet wide....You haven't posted the dimensions of your 1000 square foot space, so I don't know how wide or deep the space is, but assuming that it is 40 feet deep, your walkway will be 4ft x 40ft + 160 ft.

Do you need a sales desk ? How big is that ? Perhaps 40 square feet ?

With the walkway and the sales desk you have a total of 200 square feet devoted to space that cannot be used as furniture display.

1000 sf - 200 sf = 800 sf. which is the amount of space that you have left for furniture display.

With 800 sf, you can divide by 5 room settings which gives you 160 sf per room
or you can divide by 6 room settings and that gives you 130 sf per room........

I would suggest and aisle down the middle with room settings on either side.......

It would be easier to give advice if you posted the floor plan..........