Hum, I don't think you'd be able to bag Whitney in 4-5 hours, it is more like a full day hike.
The only 14er that you can bag in such a short time would be White mountain, since you can drive up to 12k and hike the rest.
Other day hikes to cool peaks that I'd consider much more fun would be:
- Olancha (12,133'): The hike is about 6.5k feet, 20 miles.
- Langley (14,026'): The hike is about 4k feet and 19 miles via Old army pass
- Tyndall (14,025'): The hike is about 8k feet and 25 miles.
Neither of these require permits if you do them as day hikes, but they would be pretty long days.
