Seeking inspiration for a event party menu

DH and I along with SIL and her BF will be hosting an anniversary party for my MIL and FIL (wow, that was a lot of abbreviating!). It's their 40th anniversary and we'll be serving appetizers, dinner and dessert to approximately 40-50 guests. I'm looking for some inspiration for a dinner that is not terribly complicated but will look impressive for the guests. For some reason, when I think of feeding a crowd, I can only think of lasagna and while I make great lasagna, I don't feel excited about serving it for this occasion.

So, we had considered recreating the meal that was served at their wedding reception. My FIL's father catered their reception and after talking with them last night, apparently neither of them looked back fondly on that meal and I don't think a re-do would be well received. They did love their cake and I plan to make a copy of the wedding cake for dessert.

So, I'm looking for your best ideas. We can work with: 5 burner stove with oven, 2 propane grills, charcoal grill, smoker, electric roaster oven, 2 propane burners (the type used for turkey frying) crockpots and two neighbors kitchens. We have plenty of people to help with preparation. We'd like something not-too-casual since it will be an evening event and while it will be in our backyard, we are planning to rent the big round tables with real linens and lots of elegant lighting, etc.

It sounded like the back in the day meal was a mishmash of stuff set up as a buffet. I know there was roast beef, some kind of meatballs, potato salad, mashed potatoes and, "some other stuff". I wouldn't rule out something like roast beef and I don't think they'd mind that either. I just don't think going for a total re-do of that meal would wow them.

Not too casual to me means the kind of meal one might get in a nicer restaurant. I'm not looking to do cold cut trays or a spaghetti feed or a huge pot of chili kind of dinner.

We haven't made a decision yet about plating or buffet. We're still looking for ideas to throw around.

We really don't have any kind of food restrictions for this event (whew!!!). No need to avoid any kind of meat, wheat, etc. I guess the only real exception would be that DH and I are not big fans of fish (we eat shrimp, crab, lobster but not stuff with fins) so while the guests would probably love that, we wouldn't get much pleasure from preparing it.