If you use the land as security for the house, it will cause problems if you need to sell the land or do anything with it. You are effictively tying up the land for the duration of the mortgage.
Also budget for the fact that out of your pay you will have to pay the mortgage and the costs of any loan associated the furnishing of it.
You could decorate the house over a number of years as we done, and you could use second hand / borrowed furniture for the first while.