lagCisco,
I had a hard time finding what I wanted at the time. I used a 29.5" x 4mm or 0.157" OD for both the LE and Fuse Spar from Hang em high Kites and my LHS carries a 0.157" OD carbon tube from CFS that I used for the wing. I think the product from Hang em high kites is slightly better quality and if thay have the 48" ones in stock, that;s the way to go. All they had when I ordered was the 29.5" ones.
Part CT1570L - Carbon Tube Pultruded '1570' (4mm) From [link=http://ecom.citystar.com/hang-em-high/ushop/index.cgi?ID=GJHEVX&task=show&cat=SPARS%2dLong+Car bon]Hang em High[/link] is what you want. It is the second listing down on this page. Don't forget to scuff them a little bit with 220 sandpaper before you epoxy them in.