which is better

Octopus NW-110 Protein Skimmer (NEW 2009 VERSION) [OCTNW110] - $149.99 : Fishy Business
have limited space in the sump so i have to go with a small one

or

BH-300F HOB - Google Product Search

its a 55 gallon with small-med bioload

 

I would say the needle wheel. What about the smallest Octo extreme?
How much room do you have?

 

about 10 by 10

 

and that is pushing it

 

is this the one your talking about?

Reef Octopus Pinwheel Protein Skimmer 100 Gallons - eBay (item 350254779532 end time Oct-19-09 13:43:54 PDT)

 

Any skimmer for the most part that can be in sump is going to do a better job then a HoB skimmer. The 110 is a great skimmer and i would say you dont have to get the extreme(yes, dr i love the extremes to lol) but its not really needed in this application

 

I would go with the 110 in sump fora 55g.
OP1 is right about most HOB skimmers not being as good as sump model. This is especially true when the hang on model is not a round or cone tube. Those square shaped chambers don't ever seem to work as well as a cylindrical one.