Re: carbon arrow shafts, I got the idea from Crafter who posted in the Building, Repairing and Modifying section of this forum about his Nazganic. You might want to also check this post.
I bought mine from Archery World. I called into their shop which is just off the junction of M61 and M65 near Preston. IIRC, I bought 8 for £24-99 (£3-12 each). It was quite good as in the shop you could select different types - I got 4 x 500 (P200) and 4 x 400 (P300), whereas online it looks as if you would have to buy 8 of the same type. Have just had a look on their website and they are now charging £48 ! That's a lot of inflation in 18 months !
At £6 a shaft, I don't think I would recommend them. I've not used them, but another supplier, currently charging a more sensible £3-43 per shaft (+p/p) is Merlin Archery, and it looks like you can order just the number you want. Try
http://www.merlinarchery.co.uk/easton-powerflight-shaft-only.htmlIf there is an archery shop near you, might be worth a call to see if they have any or can order any for you, to save p/p.
As I said I have 2 in my standard home-made Rev, 2 in my mid-vent home-made Rev, and the other 4 in the LE of a 2 line kite. They have all taken one or two hits, and they have all been fine (so far ! ).
The down side of these is the length not being standard kite spar length. Also I was surprised that the ones I bought were slightly different lengths (only a mm or two or three).
I've only ever flown home-built Rev's, never an official Rev, so could not tell you if there is any noticeable difference. However, I have not noticed any difference in performance when swapping Skyshark rods for carbon arrow shafts. But then ... you've not seen me fly !!!
Good luck if you decide to go down this route.