Not sure how you got an idea of a 60w camera... while I am sure one may exist, I don't think that IP cameras require that much power. Please read my post again.
Note that a pc/raspberry solutions adds more to your power requirements but does provide greater flexibility. First, select and get a camera, play with it and see if you can do with built in options. Expand from there.
I get your buy vs. build issue but if you can't find one that suits your requirements and fits in your budget (monetary or otherwise),... scrap the idea or build.
When I first started looking at cameras 2+ years ago, I thought "wouldn't it be grand to have a PTZ camera and control it remotely?". Then I looked into it some more and found out a few of those cameras were rated at 60W (but they also had a built-in heater that I did not need). Totally not serious in getting one of those and was only using it here as an example of what I wouldn't do. I have since resigned myself to a dome/bullet form factor.
I like your suggestion about building a supporting system around whatever camera I get. I've been scrapping this install for years since it seems like there are new cameras coming out every few months (i.e if I wait a bit more... maybe the wattage will be lower... maybe it will have feature X... maybe... ). I guess I'm suffering from "commitment issues"
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