in the long run i think the lvl 5 will do you good... if you deiced to get more power, you dont have to worry about your sub not able to handle it...
im using the lvl 5 for daily... equipment in my sig.... and i bearly get it past 2000watts... with a tiny truck cabin, i personally find it unconfortable to drive in...
maybe a differnt story in a trunk setup...
but yes... consider the other aspects of your setup...more batts.. bigger amp..