>Will the arcs from this size coil be impressive?

Yes, but the size of the arc will depend upon many factors, the most imporatant
of which is how many Watts of power you have available from your transformer(s).
There is also capacitor and tank circuit efficiency, secondary efficiency,
ground quality, etc.  About a million or so variables.  But don't worry about
every little variable.  Just build it as efficient as possible, within reason.
Another thing that increases the spark length is the toroid.  With a 7x22
toroid, I have gotten 50" sparks with 120ma input and a compressed air gap.
(Yes, I know I've said this in about 3 postings, but I can't get over it!)