I'm unsure that the status of XV is these days as they have been selling off their assets. Their Stage 1 kit is a nice single source bolt on set up for suspension. Other providers of similar packages would be the Hotchkis TVS kit for around $2k. However, neither of these kits address steering which could be an upgraded Borgeson box or a Firm Feel box. Speaking of which, Firm Feel can also provide suspension components, although they don't have a kit, per say, they can provide recommendations of a package of parts to have similar results to the two above.
Total cost for any of these kits plus a steering upgrade will be around $3000 +/- $500