Which setup of sub&amp will hit harder and better and louder?

Technically the second option would be slightly louder, because it will have 100 more watts running to the sub, but the difference in the two options would be almost undetectable. You could save $200 and get the first option, which would mean you are running 100 less watts and spend some of that money on getting a proper box built. The enclosure is probably the most important part of a build, and will make or break a sub stage. Going with a prefab enclosure will hold your sub back, but an enclosure built and tuned to the sub's specs and built well will really let the subwoofer shine. If you put the first option in a proper enclosure it would outperform the second option in a prefab box without a doubt, despite having 100 watts less power running it.