The tank size will dictate your filter.
The choice is what you make of it. You can save money buying used, but if it breaks, what have you saved?
For the 300-400 you can get 2 Eheim 2217's and a Sunsun 404. HOB
's are great especially with a biowheel.
It is very subjective. Scary is a big fan of Fluval filters. They are widely used and a good filter. A lot of people like them and the company is big for a reason, they are one of the largest filter manufacturers, because they are good. Eheim is also good. Sunsun is also good.
high flow rated filter with reduced flow due to media does a great job, especially with polishing floss on the top of the filter. You need to have lower flow to allow more bacterial growth.
Depending on the tank size, two is better than one. I have never heard of water being too clean for fish !
What ever you get, it will work fine.