I did a HUGE luau for my dh 30th, about 75 people.
had professional HULA dancers come in and it was a BLAST for everyone,
One even gave lessons to the adults, everyone, especially the guys loved it!
I used all round tables all covered with some sand/shells in the center and very colorful and decorated the entire yard with small twinkling lights, even in the pool and placed a spraying fountain in it as well.
I also had a GORILLA come to the house and he sang happy birthday (inside joke to my dh) That was funny as the gorilla came in Hawaiian garb too!!! (as did everyone at the party. I handed out Lei's to every person as they entered the party/yard! The pool had colorful balloons floating in it as well.
I did the cooking with help, sweet and sour chicken, honey sesame wings, BBQ ribs, (hotdogs that were in a pot with sauerkraut, cooking all day for anyone that just needed a snack, that went over very well actually), I think people just thought it was fun to have and certainly not luau..ish but good for the kids, we had chicken and broccoli dish, rice, 2 salads, I cannot recall all the apps, but I recall buying lots of seafood salad and having displays with crackers...Oh and TONS of fresh large shrimp, on skewers and with garlic and on the grill, YUMMY!! Shrimp app as well.
For dessert I did single scoops of vanilla ice cream with a bit of coconut on them. I had them prepared and in our other freezer and then Just before serving (to the adults) I added a splash of Kahlua.MMmmmmmmmmmm I had a smaller birthday cake as well. Some people were nice enough to bring a fun dessert as well, I remember someone making chocolate pieces that looked like shells, they were so pretty.
The yard had lots of Hula Hoops all around and people were having such fun. I made the HUGE paper flowers that were scattered everywhere out of tissue paper...It was BEAUTIFUL!!!
That was a VERY long day into evening party for sure. What great memories, thanks for reminding me, I needed that today!
I think this summer we are actually doing a FIESTA party for our family (thats like 50, UGH!) but should also be lots of fun!
Good luck with whatever you decide....Google away and you'll get some great ideas..

WE had a bar set up with Margaritas and Pina Coladas, that and soda and water bottles was all I served that day ( a friend manned the bar)