I will take your advise in relation to this and put a whole kit in inc coils....I have not done one before but I'l take my time and read up on the above sites for tips!

I've asked Mark for a price so will wait and see.  If I can offload the F14 plastics I bought and no longer need that will offset the price a bit...

You almost never need to replace coils.  Coils rarely fail actually.  Only three reasons to replace them

1) Someone put the wrong coil in.
2) If the coil sleeve won't come out without lots of brute force.  usually means the coil overheated and the center of the coil would be warped (which you can usually see if you look through it)
3) Coil just doesn't work.

Other than that keep the old coils =)