This is a family reunion, not a birthday party for a 2 year old. Take it easy on yourself!
This "mom/party" thing is absolutely out of hand. People are breaking the bank and going crazy for three hours of overstimulation that the toddler does not need and will not understand. As your child gets older, you will feel pressure to invite 25 children (plus their parents and siblings) to an expensive free-for-all with a pony, a clown, a bouncy house, $10 goody bags, and renting out a state park to accommodate all the guests. You will absolutely HATE having to write 25 thank you notes and then spend every weekend at someone else's birthday party for which you bought a $30 present. ("If they came to our party, I must go to theirs.") The birthday child either has a massive gift-fest and spends the day opening a treasure trove of presents, forgetting to say 'thank you' about halfway through and having no idea how to handle duplicate gifts, and the other kids sit there bored to tears watching all the things they are NOT getting. So the host family feels the obligation to give an expensive party favor. And so it escalates. People are going into debt doing this sort of thing, but at least they are too exhausted to notice!
A two-year-old does not enjoy this sort of thing. Neither does a five-year-old. It's really about getting the whole family together and having a big reunion with lots of freedom to chat in this corner, connect with Cousin Susie in that corner, and so on. That said, a self-service buffet sounds easiest with some of those chafing dishes from the box store (keeping the kids away from the Sterno) so that the food stays hot and people can nosh over a period of time.
Your child will not know what you got her because a) she's 2 and won't remember, and b) you are, as you said, having 50 people who will get her everything else. Don't worry about it.
We never did anything on this scale, and our son has grown up happy and not feeling deprived!