I've never used one, but a lot of folks say to avoid a wet/dry filter. You should be able to DIY a sump for your tank instead, depending on the interior dimensions of your stand. As far as a pump goes, ensure that your overflow can handle what it puts up. Check out this link:
Reef Central Online Community to figure out what kind of pump to use on your return.
As far as the livestock, this is the only issue I have with "The Package" from TB Saltwater, but this is based on my personal preference. Personally, I avoid hermits, too many horror stories of them munching on snails and corals. Also, Tiger tail cukes can grow to 2' in length, depending on the species, I had one in my 50 and it was plenty.