Hello,
I really can't tell you if anyone rents reasonable road bikes in the area. I would like to think that a close-by LBS does so. vladav's suggestion is a good place to start. La Habra Cyclery sponsors a race team and someone on this forum may belong to that team.
The roads in that area are a little hit and miss with respect to safety. Turnbull Canyon is a popular climb in that area and East and West Roads are a lot of fun. However, I only ride them on Sundays so I'm not sure how much traffic you'll encounter on weekdays. All of those roads are narrow. Another main road that is a bit wider and safer is Colima. You might want to get in touch with La Habra Cyclery to find out about local rides. Also I just checked and Team Velocity has a web site with rides listed in that area (
http://www.teamvelocity.org/).
Finally, my club, Lightning Velo (
http://www.lightningvelo.org/), rides out of Long Beach and we have rides on Tuesday, Thursday, Friday, Saturday, and Sunday.
Wish I could help you more with finding a bike.