You are correct in knowing that the difficulty getting him out of bed is a sure sign that he is not sleeping enough or not getting quality sleep. Most children his age need 10-12 hours of sleep per night. The more active, the more they often require. Not getting enough sleep poses many risks. It can stunt growth, decrease mental ability and increase his chances for childhood obesity--to name a few.
What time does he have to be ready for school? Is there any chance that you can wake him up later in the morning?
No, 7pm is not too early, but you will have to have all your children going to bed at the same time. It will be difficult with summer approaching but there is nothing more important than sleep. The ritual will have to start earlier in the evening and you should expect it to take about 30-45 min. You will want them to avoid TV, loud music, and the computer at least one to two hours before bedtime; this is a great time to read to your children. Also, stat dimming the lights to get your family ready for sleep. Caffeine should be avoided six hours prior to bedtime which means that 12pm would be the last time he could have soda/tea.
A great book for you to educate yourself about sleep is Power Sleep by Dr. Maas. Chapter 12 is great. It is a fantastic resource for you to utilize and you can pass this great advice on to your children. Keep in mind that a person that is well rested will wake naturally without an alarm or a mother.
Your pediatrician can be your best resource so I would consult with he/she to help you with your concerns. Most sleep problems are poor sleep habits; however, some children have obstructive sleep apnea so if he is snoring or gasping and waking himself up at night, he may not be reaching the important deeper stages of sleep which could be why he is not well rested. Keep in mind that many children snore so you will want to exhaust the sleep habits before jumping to a medical reason. This link is a good resource to learn about OSA. http://pediatrics.about.com/cs/sleep/a/sleep_apnea.htm