Managed or Unmanaged, do you want to have full control over the setup or do you want them to basically set up your web server add and adjust the major shit. There is also comanaged which can get pretty damned expensive.
Are you slinging downloads of this software product or is it something that is running on this hardware. If your slinging files you are going to need to know what kind of speed you want and how much bandwidth your using. 100 Mbps uplink is pretty slow as 10 customers can pull 1.25 MB/s down theoretically. But if you don't anticipate more than a few simultaneous downloads this might not be an issue and 100 Mbps unmetered is fairly affordable.
I used to host for several android developers and everyone loved me because I had a 1 Gbps uplink i was dishing out firmware as fast as some people's 125 Mbps cable could pipe in. Problem is the line was metered. I made the mistake of taking on an oem firmware leak operation. One morning a 4.1 Jelly Bean leak hit for the the AT&T Galaxy S3 and we were talking GB per minute of usage. I have a feeling your usage won't be like that but still have to gauge needs if you want an uplink that can easily handle 100+ downloaders at a time.
The other thing is think about VPS's and please stay away from 99% of the companies out there. If your dishing out product files then your write you don't need a super server. Especially if its on 100 Mbps. 1 Gbps will rape a mechanical raid setup if your dishing out a lot of different files but at 100 Mbps even a shared raid on a VPS won't choke. I was doing it all on NFO's VPS's under windows 2008 and 2012 and were talking 20, 30, 40, 50 bucks a month.
On a dedicated unmanaged box when something goes horribly wrong you may end up dishing out alot of money to have a tech do a reinstall. Most unmanaged plans allow for free restarts and OS reinstalls so its not always end of the world expensive. But with an unmanaged VPS if your end goes belly up a reinstall is pretty easy and you can VNC to the virtual guest as if you were sitting in front of it so even if the ethernet driver isn't installed you can still login and work inside windows until the problem is fixed. You don't get that with a dedicated server unless of course your running virtualization on it which hey alot of companies do.
