Wa alaikum salam
1) Engine missing doesn't always happens if you have a weak spark plug. But if you must need to change the spark plug, iridium tip spark plugs are available at any high end motor bike shops. Iridium plugs are expensive but run thrice as long.
I suggest that you get your bike checked for other possible reasons of miss fire before investing on performance spark plug. Note this spark plug wont make any more power it will just assist to make the start, idle smoother.
2) Buy the original factory spec CDI unit from any Honda bike shop. Please don't go for cheap china copies.
