I'm not paid to develop something or cobble something together. It needs to work now.
I've seen these Gage cards and heard very good things. So far it's the gage card vs. the keysight/aquiris. Could you explain a bit more about how they compare?
Aquiris hasn't been part of Keysight for a couple of years now. My impression is it was just not a good match. They are a Swiss company. Like a lot of smaller firms, they are looking for the big customer who will develop something around their products and wants to buy 100-1000 eventually. Not to say they won't work with a one-off customer, just be aware they may be focused on a different problem than you are.
There's a third option I'd forgotten about - Teledyne SP Devices. I saw them at a trade show. They have cards that seem pretty powerful but are much more than even the Aquiris. I forget if they were PXI only. If a giant company with top level customer support is important though, and money is no object, they may be the only choice of these three.
My suggestion is to define your must-need specs, and go through the data sheets of the most appropriate choices at the two/three companies, and get fresh quotes. If they have demo software, get that (GaGe used to). Look at the API documentation. If you have a big budget and lots of time and flexible spec needs, it could be a headache to decide, but then maybe you can get a demo card from each. If you have a modest budget and less time to shop and need to start working, then I'd say go for the GaGe and forget the others.