I'm trying to figure out which convertible seats to get for my 15 month old twins. They are 28" and 23 pounds. The seats will be going in a 2002 Freightliner Sprinter 10 passenger high top van. The 2002 Freightliner Sprinter was re-branded in 2003 under Dodge from my understanding. There is no LATCH and no tethers. I have been told that based on the weight of the vehicle tethering isn't necessary but not sure how true that is. I would love to stay under $150 for each seat if possible, but can go up to $200 each if necessary. I would like to rear face as long as possible. Anyone have suggestions?