There is no real preferred approach, no hard and fast rules in place.
Basically comes down to what fish you want, budget and space allowable.
Cannisters take up more space, so a cabinet or stand to hide the filter inside is a good idea but if space is at a premium then consider hang on back filters (HOB) as two of those in a 200l tank will be fine or internal filters, am a fan of the U series of Fluval filters, does exactly what it says on the tin but some keepers consider these to be bulky and takes up precious tank space.
However if it is a cannister filter you want and more specifically Eheim or Fluval, I have had both brands in various types of filters, both are very good names and ones I usually recommend anyhow.
Eheim tends to be more expensive but their filters are of half decent quality and lasts for quite some time also usually a tad bit more powerful and their information tend to be fairly reliable.
Fluvals are good also but a little less quality build than eheim but nonetheless still very very good, flow output tend to be a bit hiss and miss as sometimes it is confusing about their informationbeing either based on filter media be present or without media, not always clear. But still a good option once you know what sort of flow you require.
And some external filters do have some sort of flow control, meaning you can have max flow output or lesser flow, not all externals have this but some do so that may help you decide.
Go into a LFS that sells these but not to buy there and then but to have a good look at them, handle them, open them up and see what you feel, build quality and would not bother asking chain store staff about the filters as most really don’t know about fishkeeping stuff (well, very few staff know what they’re talking about but few and far between!) so trust your own judgement on build quality and ease of access and what extras you may need such as hoses, clips and spray bars or nozzles available to each individual external.
It is one thing to look online and looks at pictures etc and talking to members about filter recommendations which is fine but always best to go into a store and see for yourself so you have a much better idea of what to expect to avoid disappointments.
Edit- oh by the way, would only recommend one external filter as two would be a bit overkill and would take up quite a bit of time to do maintenance which quickly becomes a bit of a chore, there are all sorts of external filter sizes to cope with just about any sized tanks.