Has anyone gone to either of these two parks? We have two boys and want to stay in that area for awhile? (Assateague and Ocean City). We would appreciate any suggestions .... Also, at the National Park - any suggestions between bayside and oceanside? Thanks for your help!

I haven't stayed at either of those two campgrounds, but I have stayed on the Island and by Ocean City.
I prefer the ocean side of the Island. If you get an breeze off the ocean it keeps the green head fly's and mosquitoes away. A quick walk to one of the nicest beaches around. Make sure you store your food inside when you leave. The wild ponies will make themselves at home.
We have been staying at Frontier Town, when we go down. You will need reservations and make them early. Your boys will love the water park. It seem a little pricey, but if you factor in the park is free for campers it's not to bad. They charge outsiders $20 to get in per person.
We have been going down there for 8 yrs now. It is a great area.

Thanks for the advice - we booked the National Park and Frontier Town - can't wait to see them!

You will have a good time. There is so much to do there. It is getting hectic down there in the summer, especially the weekends. We try to do the boardwalk trips during the week and hang at the campground or the beach on the weekends. The weekends are nuts getting there and back. Frontier Town does have a free bus to OC and Assateague Is.
I forgot to mention, the bay side, of the national park, allows generators at certain hours.
If you want more info, I will be glad to help you out. Just let me know. Have a great time.