javapro - You are getting some good advice here from people who know. Forget about a guide service. I don't think there is one for the main trail. No one needs one for that anyway. As someone once said, the Whitney day hike requires mostly stamina, determination, and a good pair of boots. Fran and I summitted 5 times. Here is what worked for us. YMMV.
1. Do workout hikes at altitude. We were fortunate to live 45 minutes from Mt Baldy (10,064') in So Cal. If you don't have elevation available, then prepare to arrive in Lone Pine several days early to do some hikes at altitude. Horseshoe Meadows comes to mind as nearby. A paved road leads to a trailhead at 9900'. A variety of hikes are available here.
2. Start taking the herbal supplement gingko biloba about a week before your hike. It is available in the vitamin section of any grocery or drug store. Several studies show it helps with altitude effects.
3. Take some aspirin when you start as a preventative.
4. Be well hydrated before you start. It's dry at altitude. Drink water and sports drinks on a schedule. If you wait until you are thirsty, then you are already dehydrated.
5. Take foods that you enjoy eating as there is some loss of appetite at altitude. Favor carbs and fats over the harder to digest proteins.
6. Don't carry a lot of water. Water is heavy. Use a filter pump or sterilizing tablets and refill water bottles from creeks and ponds. Water sources are readily available along the trail until you reach the high camp Trail Camp. Fill at least 3 liters per person from the pond for the dry push to the summit. There is a spring about 1/3 way up the switchbacks, but it will be frozen before sunrise.
7. Tom Harrison makes a good map. Be familiar with the landmarks. You can hike to Lone Pine Lake without a permit. Do it as you will see in daylight what you will be going through in the dark.
As I said, this is what worked for us. It may or may not work for you. It may or may not be what anybody else has done.
Good luck and please post a report.
