I don't think you necessarily need a fulltime sysadmin - contract sysadmins do exist (hi!) and systems like Chef can be readily understood by most developers.
If I was moving a start-up from Heroku to self-managed hosting (which could even just be Linode VMs!) I'd include time to train them on what I was doing, and why, and I'd probably stay on retainer for emergency support.
Personally, I'm also more than happy to chat to local start-ups informally and share my experience. (And if anyone in Scotland, particularly the Edinburgh area, wants to take me up on that, my email's in my profile blurb.)
If I was moving a start-up from Heroku to self-managed hosting (which could even just be Linode VMs!) I'd include time to train them on what I was doing, and why, and I'd probably stay on retainer for emergency support.
Personally, I'm also more than happy to chat to local start-ups informally and share my experience. (And if anyone in Scotland, particularly the Edinburgh area, wants to take me up on that, my email's in my profile blurb.)