4+8 Harvia countdown timer part number is ZSK-510
I got mine from www.saunainter.com/en/sauna-spare-parts/spare-parts-for-el--heaters-harvia/timer-for-harvia-vega--zsk-510/harvia-zsk-510/#close for about $75 USD including shipping.
40Amp z-wave switch
I got this a while ago - it didn't have the "Enbrighten" branding then. Best match is here www.amazon.com/120-277VAC-Electric-Compatible-Certified-14285/dp/B00YTCZZF0 for $148 USD
Hub
Got a used one on ebay. Here's a sample search www.ebay.com/sch/i.html?_from=R40&_trksid=p4432023.m570.l1313&_nkw=smarthings+hub&_sacat=0 $60 USD
Total $283 USD