Here is my normal UK luthier and parts suppliers list

https://www.rothkoandfrost.com/
https://tonetechluthiersupplies.co.uk/
https://www.chrisalsopguitar.co.uk/shop/
https://www.northwestguitars.co.uk/
https://www.allparts.uk.com/
https://www.wdmusic.co.uk/

As the kit has binding, I'd go for a water-based stain, as spirit/alcohol-based stains get into all the thin pressure cracks in the binding and can't be removed, whereas water based stains don't penetrate the cracks and sit on the surface and can be removed with a light scrape with a sharp blade.