You can look at Masternodes.online https://masternodes.online/ and see which masternode you'd like to run and also compare ROI and cost to own a masternode.
Once you've selected which blockchain you'd like to support (based on cost of acquiring a coin or a project you really would like to support), you can select a VPS to ensure that your MN runs 24x7. You can use Nodesupply (full service VPS), www.node-vps.com, Vultr, Digital Ocean and many other VPS MN providers.
You can also run your own MN at home but keeping it up and running 24x7 might be a pain so I prefer to use a VPS based on experience.
Hope this helps.
