While indicating menu choices on the response card is not proper according to the highest standards of etiquette, it is a practice that has become widely accepted. The best way to handle the three options is to include a space before each option on the response card.
As with anything, less is more...the simpler you can make things for your guests, the more likely you are to get accurate responses. You may even consider a short line after "are pleased to accept". I am suggesting the following items without taking into consideration food allergies, etc. I'll also suggest some vegetarian-only, low-sodium, and other alternatives.
Swedish or barbecue meatballs are always a favorite. These can be served alone or with lightly buttered linguini offered nearby. Lasagna is also easy to make and serves many, as is spaghetti. Sides of steamed vegetables (spinach, broccoli) and garlic bread are both easy and economical.
If you'd prefer some American dishes, boneless buffalo wings, coleslaw, and pulled pork barbecue can also serve many at a lower price. Another good choice (and good for kids) is homemade pizza. You could have this along with some French fries for anyone who may not like anything else.
Eggplant parmesan is a good choice if you have vegetarians or people on low-sodium diets. Lightly seasoned chicken breast is also a good choice for people who are concerned about eating heart-healthy.
Also make sure you have whole-grain rolls or bread available and a do-it-yourself salad bar is sure to be a hit. Start with a big bowl of chopped lettuce and red cabbage. Put out bowls with cucumbers, celery, mushrooms, carrots, grape tomatoes, raw broccoli, and other salad accompaniments. Choose at least 3 salad dressings and oil and vinegar dressing.
For a reception that large, you will undoubtedly be cooking a lot of food and some of it (like the meatballs, etc.) may be difficult to keep warm. Be sure to invest in plenty of chafing dishes and sterno. You may want to cook a lot of the food in advance and then freeze it.
If your reception area has a kitchen, you can start thawing or cooking the food in the oven the morning before the ceremony. Have two or three people continue to thaw and cook the food during the ceremony so that the food will be warm by the time it needs to be replenished then keep them warm with hotplates or sterno. Things like chicken, meatballs, etc. can be kept warm in crock pots and the crock pots can be switched out when the other one is empty.
I personally like buffets best. Guest can pass on what they do not want and get what they do like. A properly chosen buffet can satisfy likes and dislikes and dietary needs. With a sit down there is the meal and that is it. Also if the entree is one that is not so good you are stuck with it where on the buffet you still have choices.
You could serve appetizers instead of a full meal. I think it would save considerably on the cost. But the only problem that you will have is that when your guest get there invitation that will assume that there will be a dinner after the wedding.
While I understand both points I believe they are following the line. That when you are keeping the people (your guest) over a dinner hour that your guest will expect a full meal and a meal should be served. If your time is between meals then the appetizer reception would be proper when it is put that way in the invitation.