Have a look online on metabo asr 35 m or starmix ipulse they even make it for mafell. Was looking on dust extractors for quite a while. Ended up with metabo its class m cost arm and a leg but its worth it. Using it for general cleaning but also for grinding floors chasing walls you name it. As far as i know you got 2 generation of m class extractors. 1st is the one like bosch, dewalt or flex have self cleaning of filters based on time intervals as to 2nd generation is based on drop of suction. Onced is registered it start cleaning filters to maintain suction level to protesct user.
Extractors are classed more less as follows
Class L - low mainly general dust. Wood shavings etc.
Class M - medium dust harmful to user. Silica dust (hardie boards) very fine dust.
Class H - high all above plus toxic dust like asbestos you have to use special bags
Then there is another class that i dont rememer the letter for it. But you can use it on bomb sites as its use water while hoovering.
Thats my 3 pennys added.