Ok after perusing and lurking about a bit I was looking at a builds using two Infinity Reference subs per box.
Seems to be a popular build right now and seems to maximize my Christmas gift to myself. I paid off my Yamaha amp so onto this now. The LSi9's sing but need something on the bottom.
Any suggestion (are there 12" Polk or other drivers I should look at). Also I could do two Dayton HF (but two and not four). Not sure what I am gaining or losing (volume obviously) but the Daytons individually are better but are they 2.5 times better? 10" drivers don't seem to save me much budget wise.