Those of us in the US are probably used to dealing with air volumes in terms of cubic feet per minute instead of cubic meters per hour. 1 cfm = 1.7 m3/h, so...
I currently have a HPLV dust extractor, which has a low rate 183m3/hr (the bin style dust collector)
183m3/h / 1.7 = 107.6cfm
Given that rate and your description, it sounds like you're talking about what's often called a shop vac in the US.
I want to upgrade to something with more suction - so I started looking at a dust connector with more suction... I assumed the models with 1150m3/hr would do the trick,
1150m3/h / 1.7 = 676.5cfm
A dust collector in that range is a pretty small unit, (like this Jet model](https://www.amazon.com/JET-DC-650BK-Dust-Collector-Filter/dp/B001F0R7H8). It probably comes with a 3/4 horsepower motor, and it's really only suitable for small systems. Best if you connect it directly to the machine you're using.
but reading up, these are apparently HVLP collectors and they don't deal with dust well.
The big reason that these small units don't deal with fine dust very well is that they often come with filter bags that don't trap fine particles. The one I linked to, for example, comes with a 30-micron bag. The dust may get sucked into the hose just fine, but the fine stuff will just get blown right out through the bag. You can buy a 1-micron bag that'll do a much better job for a few dozen dollars, or buy a model with a better filter. This one is the same as the one I linked above, but it comes with a 1-micron pleated canister filter.
Another option is to keep the 30-micron bag and locate the dust collector away from the work area and where it can exhaust the air to the outdoors. That can work if your shop is in a garage, for example, and you can just stick the collector outdoors while you're working, but it's not so great if you have a basement shop or neighbors who would be annoyed by the noise.
I'm assuming I'm missing some key information here, like flow != pressure.
Well, flow and pressure are related, but you have to take the size of the pipe into account. A home shop dust collector generally takes a 4" hose, whereas a shop vac will take a 2.5" hose or smaller, so the dust collector is sucking the air through a pipe with a cross section that's 2.5 times greater. Machines will often differ in exactly how much suction they can provide -- this is called "static pressure" and is usually measured in inches of water.
But I think the big thing that you're missing is the filter issue described above. A proper dust collector with a quality filter bag will be a huge improvement over the shop vac that you're using now.