Should we start with a simple hosting and the move (which may be hard, if in the future), or should we start buying a VPS or something like that?
We are developers but not so into the technical (server config) part, so we are a bit clueless here.
Thank you for your answers! :)
One thing that I really like about their support is if they do something on your server for you, they will send an email of exactly how the went about accomplishing the task i.e. all the linux commands they used. From what I have found, it also looks like they by far have the best prices for a managed VPS.
They also offer dedicated boxes so if you outgrow a VPS than you could always upgrade to one of those.
Having said that, Softlayer has a program called Softlayer Catalyst where they give you $1000/month in hosting expenses, mentoring and some other stuff. You can read more about it and apply here: http://www.softlayer.com/partners/catalyst
Does VPS need more maintenance than a shared hosting?
VPS do need a lot more work (not sure if I'd call it maintenance) than a shared host since you'll be installing everything from zero and after that you're the one in charge of making sure it stays running. But again, even that if preferable to using a shared host.
Best to cross the scaling bridge only when you come to it.
We recently switched to PagodaBox, because I have no interest in handling sysadmin stuff at the moment, and I'm loving them (writing a blog post about it soon).
Cross the scaling bridge when you come to it. In the mean time, find something solid that just works for now.
It doesn't take too much effort to get Debian working if you don't need too complex of a configuration, and unless you have 10k users it's relatively easy to learn as you go.