24MM bands are the way to go (for the 42MM adapters)
Do a search on Ebay, Amazon or just google "24mm watch bands"
3rd party leather bands work well, I've seen some stainless steel both black, brushed steel and shiny that look pretty decent. Some IMO look pretty bad. It's all a matter of taste.
I got the leather buckle. The SS connector and buckle give it a nice contrast IMO. things look boring it's all blended together. It adds a nice accent to the watch.