A buddy of mine caught one at the marlin friday night while chunking for tuna. Swordies can be caught year round and can handle water temps not to far above freezing ( longliners in the northeast catch them in water as low as 42 degrees). The only issue with catching them in the winter is getting decent weather to get out to them.
It can be done with 30's, most use 50's & 80's. There are a lot of pups in the gulf. More than likely you would be fine using 30's. However, if that slob swallows your squid, you will wish you had an 80.
30's will work fine for most swords as long as you have braid backing. We use 65 and 80 pound backing and put a 100 yard top shot of 80. Doing this you can easily put 750 plus yards of 80 pound on a 30. I like big game hollow core cause of its diameter, I have 850 yards of it as backing on my Tiagra 30W's and still have room toget 100 yards of 80 pound for my top shot and a 200 pound wind on leader.