I would go with a white dress. What size do you think she'll be in? JCPenney has dresses in stock up to 12mo all year round.
http://www.jcpenney.com/dotcom/jsp/s...equestid=39972
But for something of high quality, with a price to match, I'd look at Janie and Jack. They have two on their website that would be beautiful, sizes up to 18-24 months (but in my experience their sizes run big). I'm nowhere near retail options either, so I've only bought online, never been disappointed with J&J quality. So pretty!
http://www.janieandjack.com/shop/dep...SizeSelected=0
http://www.janieandjack.com/shop/dep...SizeSelected=0
Something else to consider would be to wait until spring if you think the baptism won't happen until then, since after January stores will start putting Easter dresses out, and you might find something you like in person that way rather than online, although those options may not be all white.
DS- 6/09
DD- 4/12
It's a boy! DS- 2/15