This may be naive but it also seemed like the integration might be easier with one adult rooster into a flock of hens than if I try with several younger mixed male/female birds from a straight run batch.
I think I could manage the mess, although now that you mention it, disposal of the waste for a proper quarantine might be an issue for me depending on the volume. I'm guessing I probably wouldn't do it all properly just out of inexperience if nothing else. Still, even if I couldn't do things the highest security way, I feel like I should at least keep a new bird separately for a little bit to ensure there are no easily preventable surprises. Maybe get a fecal float done before introducing.
It would definitely be one of the harder aspects of things for me but I know sometimes it's necessary. How hard would depend on if it was mean from the start or a huge personality change. Mean from the start I don't think would bother me a lot, but if I raised one from an egg that seemed like it was going to be a good boy and I got really attached and then it suddenly turned evil, just to save myself the dissonance I think I would still prefer to ask who in the area wants a free soup bird. A lot of people do that and they always seem to go fast.
One of the first things that got me interested in chickens a long time ago was descriptions from a family member whose job took him to somewhere that had a big field filled with either those or a similar breed (it somewhere in Guam maybe? I don't remember exactly). They are lovely birds!
I was thinking something on the smaller side since one of my little Dimple girl being just under 3lbs. Beyond that though I've been really torn on what to look for breed-wise. The year-old ones I saw looked to be bantam brahmas or cochins. The feathered feet did worry me on those though since it can be so wet here. One thing I need to research more is what happens to sizes of the offspring and eggs if I cross a bantam with a standard; currently I don't know if that'd get me bantams or a mix, etc.