Honestly, there is no perfect wine to give, because guests enjoy different types of wines (or don't like it). You'd be better off giving one type of white and one type of red, if that's possible.
Dont know how hard it would be for you to do this but... where i work we sell a 1.99 bottle of wine, 5 different flavors, so if you had something like that where you work, you could make your own label for all the flavors and guests just pick, that would be a more budget friendly way, and most markets do the buy 6 get 10% off...well where i live they do, good luck
I would vote for white wine. From what I have seen, people who don't usually drink wine but will if offered will choose white. It is not as strong and appeals to a wider audience. I'd stay away from anything too dry.
I would go with the Pinot Grigio. It has a pretty universal appeal and goes with a lot of foods. I find Moscato to be too sweet to drink alone or with dinner, as it's more of a dessert wine.
Re: What type of wine would be beest?