Congrats on the new barrel!!
There's a strong possibility that the syn forend will definitely affect how it shoots, I haven't had great luck with the syn forend on any handi, the wood stocks are much more user friendly as far as tuning for accuracy. I'm not saying it can't be done, but due to fact that there is no forend spacer, all fitting must be done at the screw hole and is pretty much permanent.
If you were ordering a stock too, unless you bought a used one of course, why didn't you send the bare frame in and order the stock at the same time?
Tim