It’s Linden Wade’s company, originally known as Sono Jingles. Their initial offerings were sonovox produced by Linden himself, which are still available. They are based in the UK, but do use Dallas singers for their group voccal sessions – I believe they work with Johnny Hooper’s company Radioscape on the vocal sessions, and are now also their UK representative. But they also offer resings from Gwinsound, CPMG/Ben Freedman, Ken R, and Phoenix Productions packages in the UK and elsewhere (including the US), at a lower price compared to the big Dallas names. The demos on the page you linked are from their own sessions, and they’ve also posted the jingles they’ve produced in each vocal session on their SoundCloud.
I did have a few sung cuts done for myself back in the summer of 2022.