Not sure on the size but you could always do this.
http://www.summitracing.com/parts/ear-991951erl?seid=srese1&gclid=CIn2-_yWlbsCFdiUfgod_i4AGg
Not getting rid of the banjo bolt but once its tight you wont have to with it again (heck weld the thing into place)
Otherwise just search google for size of bolt to an fitting Take the banjo bolt part to the parts store and figure out the size it is.
These don't seem to be a typical part that you can find anywhere so online is you best bet.
such as this google search was "12mm to an fitting"
http://www.summitracing.com/parts/ear-9919efgerl?seid=srese1&gclid=COL6q7iXlbsCFStBQgod_kUANg
http://www.summitracing.com/parts/ear-991951erl?seid=srese1&gclid=CIn2-_yWlbsCFdiUfgod_i4AGg
Not getting rid of the banjo bolt but once its tight you wont have to with it again (heck weld the thing into place)
Otherwise just search google for size of bolt to an fitting Take the banjo bolt part to the parts store and figure out the size it is.
These don't seem to be a typical part that you can find anywhere so online is you best bet.
such as this google search was "12mm to an fitting"
http://www.summitracing.com/parts/ear-9919efgerl?seid=srese1&gclid=COL6q7iXlbsCFStBQgod_kUANg