Sounds good. Again, where you are going is very remote and with the exception of Black Sands Beach which is close by the water is too rough for snorkeling on most days. Do your wife and kids have plenty to do there? As I stated earlier, there are no restaurants or shopping or ocean excursions of any kind. As far as vehicles, a van definitely won't do it. The problem there is lava rocks and the need for clearance. Also, the district where you are going is Kau [Kah-oooh'] which has a lot of mud and even 4WD often won't cut it. Guys use ATV's or walk. The terrain is steep and heavily brush covered. Access is difficult because much of the public land is landlocked by private land. Really tough area to hunt without dogs. If you do plan to hunt, make sure you contact the Hawaii DLNR and apply for a Hunter Exemption. If you have taken an approved Hunter Safety course here on the mainland and have a certificate, you need to fill out a form and send a copy of the certificate in. It takes about a month. They will send you the exemption form and number which you'll need in order to apply for a hunting license. For fishing, no license is needed.
Look forward to meeting you. Maybe we can get Steve to join us somewhere convenient.