Ive used the aquatic life, aquaeuro, tunze 9002 and 9004 (my favorite), remora, Have used aquamaxx ws-1 and currently the hob 1.5 in sump due to the hanging bracket being damaged, the aquamaxx being another great nano skimmer. I did the air line mod on the aquatic life and even then is wasnt that great. I would go for a used 9001,
Or aquamaxx. You can Sometimes find good deals on eBay. I found the Hob 1.5 for $50 free shipping,
That was a hell of a deal.