Well first you'd need to make sure your tank can be drilled. The ghost overflows are bulletproof in my experience, so long as you set it up correctly, but they're a bit expensive. I would upgrade to a Reef Octopus HOB skimmer, they're not too expensive and work extremely well. I also recommend a Hydor canister; replace the ceramic rings for sintered glass media or something equivalent in value.
You need to decide if you want a sump or not, the gear is substantially different from HOB (hang on back) models vs submerged models. Again, check your tank for tempered glass so you know if you can even drill it. If you can't, the expense might be too much having to buy a brand new tank, overflow, sump, etc.