I'm on a couple of zebra sites myself on Facebook (I suspect my wife has EDS too)
G lite seems quite popular as a budget friendly option. I looked into getting one before I ended up with my argon. Alot of people with the same condition I have (Ehlers-Danlos syndrome, we dislocate easily. Basically) so lighter chairs work better for us. Also try places like eBay and gumtree, I got my electric chair for £200 on ebay and a power assist chair on gumtree for £150. All three have their uses depending on what I'm doing that day. The g lite you are looking at about double the price of the one advertised here but it will be much lighter.
Personally use a Quickie Argon 2, which is really very light. Though you can get lighter than mine again, mines an active user one and I guess once you try those the standard ones feel very heavy, with a huge amount of play in the frame as you propel. Cutting down on weight in any way possible is beneficial if you are self propelling. Also worth a mention are the rubber rim covers, excellent on any chair to aid yourself to push. I adore my wheels, I could never go back. We had one of these chairs in ikea recently as we left mine at home and it was hard work. Def look at those rim covers though. More so if your wife can self propel. :)
Misread the title as 'future-proof' (horror)