I'm not a real expert in the lowering thing, however are you lowering by changing out the suspension, springs, shorts, ???
If you are it will change the load capacity, due to clearance issues.
Now for the tow, I don't know, but you may have issues with drive train alignment??
you may want to really evaluate the whole picture before dropping a lot of money into the lowering, if you still want the tow/load capacity!!
Just a thought