Depends on what kind of skimmer comes with the tank. I'm not a big fan of HOB
filters or canister filters on saltwater tanks. Actually, to be candid, I think they do more harm then good.
As far as two skimmers are concerned, I believe it is better to have one properly rated skimmer than 2 undersized skimmers running together. Protein skimmers do more than what they seem to do at first glance. And to make it more complicated, if not set up correctly on a tank, you won't get a skimmer to act as a foam fractioner efficiently. A skimmer needs to build foam to work correctly. If there is not enough "protein" in the water, it can't build a head and dump into a cup (think beer). So, two skimmers could potentially cancel eachother out and just the same, one over sized skimmer could not remove organics from the water column to yield good results.
I take the rating of a skimmer and add about 25%. So, if I had a 130 gallon tank, I would want a skimmer rated for 150-165 gallons. I tend to stock my tanks heavily. And another thing, if you are getting a used skimmer, you can bring it back to life by running it in a bucket of warm water and vinegar for a few hours.....connecting a line of tubing to the venturi and running the water through it as well.
Congratulations on the big tank. What skimmer do you have and what is coming with the tank?