Removal of load bearing walls

Hi
I'm looking to doing the following:
1. Remove a 3m load bearing wall between garage and kitchen
2. Remove a 4m stud wall between kitchen and dining room
3. The house has already had a rear extension and I presume I will have to put another RSJ running the width of the house, the width would be roughly 8m.
-I presume I will need RSJs for the 2 walls coming out and also for the width of the house to hold up the gable end but can there RSJs be connected easily?
-also what rough price would you expect to pay for something like this?