Stumped. Need dinner party ideas for 8 some of my guests have had my standbys a siracha shrimp appetizer , summer tomato soup, pasta and lam

Do you have a barbecue? I don't know where you live, but where I am it is hot and I hate to turn on the oven! If you do, how about http://food52.com/recipes/10836-herbed-beef-skewers-with-horseradish-cream (This can be done in the oven too)
I would try to do make-ahead dishes for the sides since you have 8 guests and don't want to miss the party.
Gazpacho is a great start to a meal and better if you make it the night before.
Here is my stand-by recipe (though there are many other great ones here too I am sure) http://food52.com/recipes/18994-radish-tarragon-and-roasted-garlic-gazpacho

Do another light seasonal vegetable salad like this one:
http://food52.com/recipes/12928-dilled-crunchy-sweet-corn-salad-with-buttermilk-dressing
Maybe a nice chilled potato salad: http://food52.com/recipes/4734-spanish-roasted-potato-salad
A simple but elegant chilled dessert http://food52.com/recipes/3060-lemon-posset

You are right ....sorry I had thought about Paella but know some of my guests aren't big on seafood. I was looking for a more formal meal than we usually have... Beef would be the protein

How about a Paella , lots of choices for guests.
One dish meal ,prep ahead ,serve in pan .
Keep the theme with Sangria and Flan for dessert

It would be helpful if you had a starting point....like a nationality or a type of protein or even the mood you want to set. There are just too many options...narrow it down a bit and you will get help.