I'm currently 18wks pg with DC3 and have 2 DDs. I know I have loads of time to be thinking about names but it took ages to decide on DD2's name so want to get a head start! 
We don't know baby's sex at the moment, but will hopefully find out in a few weeks' time.
DD1 is Gabriella and DD2 is Sophia. We're don't necessarily want to stick with Italian/Spanish type names or names ending in 'a', it was just a coincidence that they both ended up like that! 
To help, a couple of girls' names that we like are Naomi and Elena and we can only think of one boy's name that we think 'goes' with the girls and that's Alexander. We've always been rubbish at boys' names so were lucky that we had girls! Our surname starts with H and is has one syllable, so would rather avoid names that start with H too.
Looking forward to hearing your suggestions! 