Home Remodel/Addition Advice

[BengalHawk62]

We are thinking of adding a large addition onto the house here this summer.  We've drawn up a couple different sketches with all of our ideas and have a couple contractors coming out to take a look at this to see if its even economically feasible.  What's the next step?  If the contractors come back saying ya, they can do this project within our budget, how do we get the funds to purchase this project?  We will have to take out a loan of some kind, but how does that loan work?   
Any advise on how to keep the overall cost of the project down would be appreciated.  The current house now is a little over 700 square feet and the new addition we have in mind is somewhere between 800-1100 square feet, no basement.  We want to add a big living room, a master bedroom and a big bathroom.  Also including a few modifications to the old house.  In the kitchen, just adding a bigger window and a dishwasher.  And taking the tub/shower out of the small bathroom we use now and adding a stand up shower.  Removing the current front door and replacing it with a big window.  (we'll be adding a new front door in the addition.)  Oh, and building a 24x30 garage in the backyard. 


For you folks in the know about line of work, what would your ballpark guesstimate be for this project?