You're right in that you shouldn't have to pay for something you are morally against, and it is certainly possible to serve meatless entrees that are good, but you have to be careful. A lot of non-vegetarians find vegetarian food disgusting (probably the same way you feel about meat, without the morality.) Eggplant and tofu is particularly offensive to carnivores. Meatless is one thing, but make sure you are not serving health food, or you will have a lot of grumpy, hungry people not ready to party. If you go with a pasta, you are less likely to freak people out. Some kind of pasta like cheese ravioli or pasta alfredo would work, and people would not really notice that they aren't eating meat. Would a meat sauce bother you? Fish has much more of an odor than other meats, so you may want to skip that. What you might want to do is get some meat eater friends together and have them sample meatless dishes--they will tell you which ones are gross.

Keep in mind, some people are going to be cranky about this, but don't worry about it. They'll get over it if the food is good. And, make sure you have a line on your pick-an-entree card for people to write in special dietary needs. Some people may need to have a special dinner made for them, and it may have to contain meat. Some people may be allergic to pasta or something, and some people actually HAVE to eat meat. My uncle (a former vegetarian) actually wound up in the hospital because of an excess of some vitamin found in plants, and they told him he HAD to start eating meat--at least fish. (He was not thrilled.) It's rare, but it happens. Still, 1 or 2 plates with meat on them will be pretty hard to smell over the other food.

Good luck!