I run an FX5 its awesome just my .02$, FX5= huge amount of bio-media and filter pad options, you can get them with media for about 270 new on amazon, a new 405 is about 116 on amazon with out media. the 405 would be sufficient if you had something else to help with circulation.
However, I run a FX5 with a 205 on mine and still have a fan for more circulation.
29g Tetra Tank
100g Planted Angel/Clown Loach
I can't spell...Im an engineer, I do math