>>7This is an EC2 cluster I use for my own stuff. It isn't costing me any extra money. As long as people don't start pulling 1TB per day. For short bursts this will scale up to a few dozen gigabits per second. I just had it available and it was less of a nightmare to configure than my OpenBSD VPS, but that's probably overkill. I'd have to figure out how to statically compile perl and put it in the jail, etc.
I'll get an unmetered dedicated server soon, but probably over the weekend this or next week, since I don't have time to set it up right now.
I can easily implement delta updating if you want. That's what your technique is called, transfer only the additions / changes. I don't think it's going to make much difference since an .xz of this entire board right now is 78KB. I'm more concerned about nginx and the perl script getting raped with hundreds of requests a second.
I spend almost all my time programming, either way.