Writing in english to you is strage as we're both italian, but just to let other understand my reply, i'll stick with it.
Pencil is very useful for letterform study and understanding.
About the penholder I find it easier with an oblique one but many start and keep with the straight. I guess it dipends on how you started and feel more comfortable. Somes say oblique is ok for spencerian and copperplate needs the straight. I think when you get how to write and how to draw curves the tool is just a friend that walks by your side.
As for nikko g you can find them in shops for people who draw manga. If you get to find them in a store you won't have to pay for shipment. (Calligraphystore has a special ship price if you order nib only)
I hope this helps.
