Sangria or Wine Cooler for large group
Liquor is quicker! and not to mention more cost effective. Make some rum punch, margarita or lemonade mixture! Simple recipe, buy Simply juices in the orange juice section of the grocery store, 50% lime, 25% orange, 25% lemonade. Then have fresh orange, lemons and limes for fresh juice and garnish. Tequila and lemonade is delish. Bourbon sours. Any concoction will do. You can even buy crazy umbrellas or plastic palm trees for garnish.. (party store) makes for super cute photos..
Peach nectar is the best with an inexpensive cava or prosecco.
As far as answering your question, for white sangria I would use dry white port and mix with pineapple juice and cut up apples and lemons in the pitcher - pour over ice and add a splash of club soda.
Decide on a couple of items and don't go crazy with choices. If it is in your budget, put an ad on Craigslist or ask a restaurant, pay a bartender $100 to work the party.
Ric - I suggest two batches, one white and one red. Both iced. One more like wine and one more like a fruity wine cooler.
The red: mirror lambrusco in the chilled red, slightly effervescent style. So a CdR or Italian red with some tannins, hen put in soda water, citrus, etc for a refreshing edge.
The white: use wine and vodka or rum. Peaches, lemon and lemon zest.