if you need only 8 seats a minivan could work, however you wouldn't much extra room and if any of those passengers needed carseats this would be tight.
If you were looking new I'd say the Ford Transit - they have a passenger version which is resonable conformtable in 12 and 15 passenger versions.
For 10,000 your really looking at the older style vans i.e. E-Series. They are very reliable due to being almost unchanged for 30 years.