First, congrats on the opportunity.
Second, be VERY careful in how the employment contract is structured.
If at all possible, you need to view your time in HK as a semi-permanent move. Six month "other-side-of-the-world" opportunities have a way of expanding to years. (Ask me how I know.) In addition, there may occur further opportunities for you there that incentivize you to stay longer, along with kids and spouse who have made new friends, acclimated to a new city, new food, etc.
Even if your opportunity is contractually only 3-6 months, I would advise to structure the deal as an "ex-pat" package. One of the priorities here is taxes. It is in your best interest to understand ALL of the tax implications on such a move, and have an employment contract that specifically states that your taxes will be equalized back to US rates. In addition, many of the benefits (i.e., employer paid housing, schooling subsidies for your kids, etc.), may become a taxable event for you here. In addition, get realistic advice on the cost of education for you kids there. Private US schools in Asian cities can get very, very expensive. Like college-tuition type expensive in some cases. Best advice I can give here is to visit with a consultant/accountant who is experienced in International employment moves.
Third, if your employment is such that you're being offered a 10-15% raise to go live there for 3 months, you’re in for a rude awakening. Especially with kids. The cost of living there (and in other big Asian cities) is WAY above US standards. My last foreign assignment in Asia was 6 years in Japan. The cost of living there (in late 1990s) was 3.3 times NEW YORK CITY. Hong Kong usually rates within the top 5 most expensive cities, so be careful.
Fourth, try to angle for a membership in the American Club there. It's expensive, and a lot of companies won't do include that for a temporary assignment, but it's worth a try. It would provide a base of familiarity for your spouse and children.
Now with those caveats out of the way, I'll admit that I've done two foreign assignments in Asia. Singapore & Tokyo. Loved them both. The opportunities were the adventure of a lifetime...
Best of luck...