No way we could even guestimate the costs, because we don't know the existing set up. As far as the plumbing goes, the costs could vary widely depending on relative access to sewer main and water supplies.
When you mention jacuzzi, you should consider a installing a much larger water heater, or perhaps even better, install a second, dedicated WH for this room.
Speaking of heat, a good HVAC contractor will need to determine if your existing system and ductwork or whatever will support the expansion. SO, choosing a good general contractor who will know who to call in for all these things is important. Normally, you should have an architect. Around here , there are some very good "design-build" contractors , who basically provide in-house architecture service. I believe this is fine when you are not building the Taj Majal.