Im not hosting neither of those services. And im looking for hosting provider recommendation. 
Then provide additional details about your cryptocurrency business. For example,
1. "We need VPS with good SLA (service legel agreement)".
2. "We don't want to use third party whenever possible". In this case, you probably need to run your own full node which require faster VPS.
As i said, so far im having doubts between Ionos and Ultahost and im curious what is the crypto community using nowdays when it comes to VPS. 
Since you doesn't mention budget limitation or other specific rerquirement, why don't you just use popular services such as AWS or DigitalOcean?