I prefer accurate, tight bass without boominess.
Me too. The importance of having four cannot be overstated. Ported or sealed, driver size and wattage all pale in comparison. Nothing I ever heard anywhere comes close to what I have now with my distributed bass array. Duke himself, if I remember correctly, had a client with a $30k budget (just for subs) and compared went with the Swarm over a lot of much bigger, more powerful, and more expensive options.
The Audiokinesis Swarm is a complete 4 sub system that will get you true state of the art bass for about $3-4k. Duke builds them ported and they come shipped with plugs to enable them to be run sealed if needed to get your desired in-room response. Tim, aka noble_100 has this and has posted lots of positive comments on it.
Another option, I built my 4 subs using Morel 10" drivers and cabs from partsexpress.com where I also bought the same Dayton amps Duke (Audiokinesis) uses. This option is under $3k even with two amps and premium rosewood veneer. It does however involve a lot of DIY skills.
Third option, buy 4 powered subs. Whatever size/power/design you like. This does matter, but a whole lot less than you’d think. By far the most important decision you have to make is not which but how many.