Whew - thats a lotta q's. 1st - I would highly recommend getting a sfb. Its the best way to manage your heat source without losing heat unnecessarily by opening the top. Its $60 well spent.
2nd - most swear by BBK (Blue Bag Kingsford), though I'm sure all would agree that "instant light" is not the best choice since it tends to leave unpleasant taste in your food. Many like lump hardwood, most say it burns hotter - though my experience is not the same. On the ash accumulation: I did a 15hr smoke yesterday in a sfb, and the temps were good right until the end (I have a CG Duo with a sfb). You might get better results with an ash can to dump ash in along the way than with a charcoal basket (others may weigh in with different/better ideas).
Bottom line - get a sfb, and use good fuel - its better in the long run. Good luck, bro.