Your question directly relates to our situation back then. My boyfriend moved in with us right at the start of our V relationship, because he was long distance as well and we couldn't manage too many visits back and forth. I have a blog (see signature), feel free to read about our start. We still live together (2nd year now) and we never encountered real problems concerning the living arrangement.
We started with a 'trial visit' and tested the waters. Everything worked fine and we moved him in. As you said, this wouldn't have been possible, if my two men didn't get along as well as they actually do. If you are sure, that you want to try, go for it
We can't judge your personalities and the odds like you are able to. Be prepared for some intense weeks emotion-wise and keep on talking about everything that comes to mind. It will help.
Facts: 30, female, bi, v-type relationship with Sward (husband, straight, mono) and Lin (boyfriend, straight, mono), poly-fi and co-primary.