I am sure others will have better advice than me.
first of all, I never get a new dog without taking my current pet for them to meet and see how they get along.
I would also suggest that you all invest in time learning dog behavior as it will greatly help you in ways you cannot imagine.
I am a big fan of Ceasar Millan, Dog Whisperer, on the National Geographic channel. But there are many dog behavorists out there that possibly folks here could recommend.
If I can be of more help, let me know!