ShaneSauce

I plan on ordering a SSD 18" pretty soon and I'm attempting to make my own box. I'm only 16 and I'm not very good at math so if you guys could help me it would be greatly appreciated. I used the box calculator over at ssa and this is what I got. The 18" SSD needs 6-10cuft and needs to be tuned at 33hz, well I came up with some numbers and I got 19.5"H/ 36"W/ 18.5"D and after displacement that gives me 5.9cuft. And then it gives me the port length, area, and volume. (Port Length = 0.722 inches) (Port Area = 7.069 inches squared) (Port Volume = 0.003 ft cubed) What do I do with those numbers? I have no idea of how to tune a port or anything like that so I will need some help. My next question is should I go with the dual 1 or 2 ohm voice coil? I don't know the differences. The last thing, I am going to power it with a Hifonics Txi 1008D Mono Amp which will give it 1000rms@1ohm. Will I need to make any upgrades to my electrical or can I run this on stock electrical? I really want this to work out and not have anything go wrong, sorry for asking so many questions. Thanks in advance, Shane