Well, a 10 is pretty small, and your choices for an external bio filter are pretty slim.
I would suggest using the filter you have now primarily for mechanical filtration-- removing things that are floating in the water. Keep your eyes out for a similar-sized used HOB
filter, or buy one new. Remove all the filter pads and either fill it with ceramic rings, or some other kind of ceramic bio media like Ehfi substrat pro. The ceramic media has a large surface area due to millions of microscopic pores which bacteria live on. With a 10 gallon tank water changes are a breeze, and you should rely more on doing regular water changes than increased filtration to keep your fish healthy.