House remodeling question

[Matthew Charron]

Hey everyone I have got a quick newbie question. So I am currently a renter and a brand new investor trying to get into the business. I don't own any properties, not even my own. However my fiancés grandfather came to us recently offering to sell is his house for 100k less than it's estimated at. The house is in great condition as far as I can tell. It's just a tad out dated and doesn't have a finished basement. I was looking to purchase with a full 203k loan as I have to put in a septic system and I would like to remodel the house. My question at the moment is... who exactly would I be looking to speak to about the design of the remodel? How to make best use of the space available. It's a 3bd/1ba about 1234sqft I believe. No master bathroom. I'd like to open up the kitchen to the dining room and maybe even the living room and would love to try an add a master bath and finish the basement. Just not really sure who to contact to get an idea of how we can use the space available to us. I know I need a certified 203k contractor to do the work but are they able to decide how to use the space or would I need an interior designer or architect or someone like that? Thanks all!