A large prop grabs more water and has a bigger bite. Sorta like 4-wheel drive vs 2-wheel. You need all the "traction" you can get to push a houseboat. Pitch is your "gear"... Low pitch, low gear; high pitch, high gear. For a houseboat you need a low pitch or you may overload the engine.
Water being a fluid you can trade-off one for the other a LITTLE, but the prop for a runabout is not going to be suitable for a houseboat. Will it work? Maybe. Will it work well? NO.
Serious prop-shops have computer programs that given the right data will pick close to the optimum prop for you... can you BUY that prop? maybe... or maybe you'll have to get the closest one and have it tweaked.
She's a tired old barge but she's paid for! http://s71.photobucket.com/alb...p;current=ef324993.pbw