Get the 1000.1 because you are more likely to fry an underpowered sub than an overpowered sub. From what I've seen, people are more likely to clip their amps if the subs are underpowered which tends to be more destructive than more power. JLs are made to be abused, that's why they cost so much.
If you can't afford the 1000.1, then get a smaller W7 or go with the W6 line.
2013 F30 328i - Melbourne Red
2011 E90 M3 - Monte Carlo Blue
2004 E46 M3 - Imola red