I am working on a custom sled for my kids and was looking for the lightest seat and tank combo available. This will be on the older Polaris type chassis. I have one started on the gen 2 platform, but also have an Indy lite that I would like to long track at a later date. I bought a dragon tank and seat combo and found that this weighs more than the edge tank/ Boss seat combo I already had. The Boss edge seat is for the kicked up tunnel in the seat area and I will most likely have a straight tunnel without any kick up in the seat area, so the newer dragon/ pro set up seemed like the way to go until I weighed the combos. I recently picked up two of the fusion style tanks both similar but have some differences in the front of the tank due to one being for a carb and the other for fuel injection (I think). These also have a smaller venting system that is farther forward (not right next to the gas filler),and looks better than the newer dragon and pro tanks, as I plan to run without a tank counsel like the old Indys to shave off some more weight (raw look). I also found that the fusion tank was almost two pounds lighter than the dragon style tank I have (not sure if the pro tanks are lighter). Not sure if it is all in the reinforcements that are not in the tank but I don't think a foam spacer would add two pounds. Still need see how this compares to the weight of the edge tank. I was also looking at your edge seat with the rear post style supports as it looks to have a front and rear support system independent of the tank that attaches to the tunnel. This would also require some mods to the rear support if I were to use this with a non tipped up tunnel, unless you offer that seat for a gen two that only had a slight rear extension tip up well behind the seat. I have seen some on the forums make mounts to attach pro style seats to older sleds but I am not sure if the weight of any adapter I could make would provide any benefits in the quest to have the lightest tank and seat combo. So with the few options I am considering I guess I would need the weight on the edge type, a gen 2 if available, and the pro types as mentioned above in the lowest profile available as this would be for my two young children 10 and 11 years old. If there are options on getting something custom built I would be interested in that also. With some weighing in at 15 or more pounds there may be others that would want something similar, as this would be a great way to loose up to 10 pounds on an older sled being prepped for younger riders.