Hey Magibeg! You are not over-thinking this. I just went through the same question and researched and obsessed for months. I'm now using an iNuke 6000DSP with my UXL 18s.
Let me summarize the conclusions I reached for you!
- puts out about 1400 watts per channel verified at 4 ohms. Realistically, you cannot get more power out of a single outlet. Has an excellent variety of adjustable filters (PEQ, LP, HP, etc.) built right in. Supposed to be really noisy, but there was a redesign and re-engineering in Q2 2015 that reduced heat and noise. Mine is 5.5 feet away and much less intrusive than my PS4. Fan mods are easily done and several are well-documented on this forum and others. There are claims of a high pass, but I get great excursion down to 2 hz. Inexpensive. Looks like donkey balls.
- I considered Crown for a long time. Supposed to be very reliable, fairly quiet, look fine. I discontinued considering them when I read several forums discussing a possible high-pass on Crown amps. In my research, I came across a forum where an actual Crown engineer stated that every one
of their pro amps has a built in high pass at 20 hz. Since you, also, are doing sealed subs, STAY AWAY. Ported would be fine, since you want ULF rolloff anyway. It's really too bad; good specs, good tests, good looks and good price.
- Wow, a brute of an amp, with pretty dreamy ULF response, and good looks. Oops, wait a minute, Class AB?!? Power drain is absolutely huge for this one. Definitely a dedicated outlet, and probably a dedicated air conditioner sue to all the excess heat at any volume level. My room was too small and too warm year-round to consider this one. Outside the listening area, with a dedicated power outlet, this thing would be a monster. Not too expensive compared to the iNuke, even though you're getting about 50 lbs more amp.
- Probably the only way you're going to get flat to 5 hz if your signal chain allows it. Would have absolutely shattered my (rather tenuous) budget. Most of them are lookers, too.
Another factor you have to consider is that the iNuke has the built-in DSP, otherwise, with any of the other choices you need to add a DSP at additional cost and complexity. Lots of people have noise or ground issues trying to incorporate a miniDSP for example.
Good luck with your research and your project! I'll definitely be following for pics and giggles.