My vote is that you should listen to the guy who understands what ackerman is.
Moving the car to S14 suspension would be a big job and unless you're an experienced fabricator, expensive.
Huxley, you know, they have very specific goals they want to achieve, and they probably see an advantage to using setups that are time-tested in the drifting world, or maybe they just have years of experience with S14 suspensions, and modifying a Volvo that extensively is no big deal for such an experienced workshop.
If you want to build a drift missile for yourself, there are options out there already, specifically for Volvos.
Kaplhenke for instance produce some absolutely outstanding go-fast suspension components.
If, on the other hand, your goals are genuinely just wanting adjustable control arms and 5x114 stud pattern, well maybe you do need to tear out the entire suspension then (though surely its easier to have someone machine new hubs with a 5x114 pattern)