Under-bed gas struts

I know several owners of Warwick Duos etc have installed gas struts on earlier models that didn't have them as standard. I would like to do the same. Could someone tell me what size/type they bought and best place to buy them.

I have just purchased these [You must be registered and logged in to see this link.] as the previous as the previous 150n ones from ebay were not powerful enough for the passenger side bench due to it not going vertical. 
Picture of them fitted on this page [You must be registered and logged in to see this link.]

All sorts of outlets from EBay to the local scrap yard which is where I sourced two for my rising solar panels on the roof of my Hym.....sorry ‘van. The difficult bit is working out length, lift length and weight

jennyandpeter wrote:I have just purchased these [You must be registered and logged in to see this link.] as the previous as the previous 150n ones from ebay were not powerful enough for the passenger side bench due to it not going vertical. 
Picture of them fitted on this page [You must be registered and logged in to see this link.]

Thanks, although those are out of stock, the dimensions are what I needed so thanks again.

biffobear wrote:All sorts of outlets from EBay to the local scrap yard which is where I sourced two for my rising solar panels on the roof of my Hym.....sorry ‘van. The difficult bit is working out length, lift length and weight

The lengths etc is what I was after, jennyandpeters link gives those.