Don't go for the international VPS host like Vultr or DigitalOcean since they're very expensive. Try to look at your local VPS in your country since they usually offer a much better deal in terms of pricing. Some may allow you to opt out SSD to the HDD storage to suit your need, in this case, 100GB for iDNA node. See, some in this thread gave you a few suggestions already.
This is true, not long ago I found out that local providers are way more cheap than the international providers like VULTR or DIGITAL OCEAN. I paid a lot of money to them for the same services.