My experience was that since the driver fired down and I'm not in fear of rodents or misplaced feet I didn't need the grill. I already had 12 AWG speaker wire. Compare prices and make sure that you actually need everything in the kit.
Typically, in sonotube, you line the inside of the tube with batting (the stuff you make blankets out of) not loose polyfil. I struggled with it a bit but I had the wrong adhesive. Try to find the spray adhesive Pat used.
I think you were looking at the 1001. The 1201 is good bang for the buck. If you're on a limited budget you can legitimately save $55 bucks and get decent performance. The Shiva will outperform it but it's up to you if you want to spend the money. If you go with the 1201 you may want to go with the 100 watt amp and save a little more money.
I think you clicked the picture for the 1002, that costs $92(it looks like it goes with the 1201 text). Click the picture right above it or on the text for the 1201. I don't know much about them other than they are a respected brand by others here.