As a pinstriper for 36 years i would recomend Asking if he would do the gold stripe in real gold leaf or vinyl leaf, most of all fire trucks are done in vinyl leaf these days. it's actualy real gold impregnated onto a vinyl membrane and is cut into shape with a plotter or can be bought in 3/4" wide rolls very cheaply.
Wether he's doing it in vinyl or not have him do one panel using the sign gold vinyl and apply the hand painted stipes to border it as he has proposed, the pinstripe paint can be wiped off up to 3 hours later with reducer and the sign gold should be easy to remove if you don't like the look.
Or another thought spray out a sheetmetal panel the same colors as your car and give it to the striper to do a test panel for your aproval.
And for future referance old pinstriping can be removed with easy off oven cleaner without damage to the vehicle paint so long as it's a good quality paint job and not a rustolium job.
http://www.quick-signgold.com/applyi...illustrations/
Scott