I also would go with a medium fast blank. One of my all time favorite nymphing/wet fly rods is a Scott G Series 10', 5wt.
Here is something that will assist, in preventing break offs, when using very light tippets...
Frontrangeanglers.com - Shock Tippets
I also use the Roman Moser "Shock Gum Loops", which essentially do the same thing: