Skip,
I'm kind of a rookie. Most of my smokes have been short (7 hours for ribs) with one overnighter. I've used lump (Royal Oak) and Kingsford and not really noticed any difference. I think the folks who notice a difference are people who pay close attention to subtle things. They notice the subtle smell of briquettes and that lump burns somewhat hotter. I’ve noticed none of that. Point being – buy some lump and try it. If you don’t notice a difference then I think it pretty much comes down to what is available in your area and how much you want to spend. Generally, Kingsford is one of those things that you just can’t go wrong with. You can usually find it, at a good price, and it burns a long time.
To answer one of your questions – yes, you still need smoke wood with lump. Maybe a little less, but unless you like just a very little smoke flavor, you will need some.