Hi-Ranch 2 levels 1200 sf
Use of whole house fan will be stopped.
No central air now or planned.
I would like to try a 1000 cfm roof mounted thermostatically controlled fan to cool the 120 + degree attic and hopefully cool the rest of the house. It will have to go on rear of house, the same side as the through the roof vents.
2 existing gable vents. About 18" x 24" each.
No soffit or ridge vent existing or practical to install now.

Questions:
1. Will I be cooling the entire attic or will I be simply circulating a small pocket of air coming in through the nearby roof vents? I have someone that can install the proposed fan. I have no one to close up the roof vents.
2. What is a better method of cooling the house in general? The old whole whose or the proposed attic fan?

A whole house fan if done properly is a great option. The reason it is so great is that you can set the path of circulation through your home. The only real drawback is that when it is in use you will have to have something open to outside air. A window or door etc to feed the vacum you will create with a whole house fan.