Unfortunately, everything Jay J says is true, except for the paint and BDry part. However, Southern California is a tad out of my service area, and the kids are still in school.
The problem is, you are looking for a vascular surgeon to remove a splinter from your finger, or an international corporate lawfirm to argue your speeding ticket. Both are fully qualified to do what you want, but you can't afford them and that isn't what they are in business to do.
The attic fan and whole house fans are not that hard to do, but they do require a little knowledge. You said you talked to all the HVAC specialists, but I will recommend MacDonald Miller as a good company in that catagory.
Beyond that, you should probably look for a remodeling contractor. One good way to do that is to contact ImproveNet at www.improvenet.com, and submit your project. Assuming you are in an area where they service, you will receive 4 prequalified contractors names who want to bid for your job.
Use Ctrl F on the main board, and search for the words ventilation, vent, fan and attic. You should find some additional postings on the topic.
Best of luck to you, and feel free to post back with more questions.