Keep your current filtration and look into adding the Rena XP3 filter. Great for the price and does a great job. When I was doing the research it was between the Eheim and the Rena XP series.
If you go this way, DFWfishbox has a link for a discount code on the XP3 in their deals section. I know it worked last month I ordered one for my son for about $110, from Drsmithfoster or fostersmith whichever way it is. Good luck.