I have a ruger hawkeye with a bulged barrel that I am going to send off to be rebarrelled. It is currently a 7mm-08 and I will probably keep it that way. From the factory, the barrel is 16". Would going with an 18" barrel in same contour mess up the balance? I like a short rifle, but this is too short. Also can any gunsmith match factory barrel profile so it fits stock?
Thanks

IMO it will balance better with the longer barrel and I'd prefer 20".I would call Dave at IT&D custom for the new barrel if you want a good turn around time on the job and dont dislike Douglas barrels.

I made a left hand one using Dave at I T D. I did a 260 with a 20" barrel. And yes, he can make the barrel the exact contour so it will fit the stock perfectly.

I am also considering the 358 win as I already own a 308 which to me is too close to 7mm-08 to warrant both. Will factory barrel contour handle a .35 cal hole?

^^^This is what I would do..

Ruger made lots of .358 with their standard factory contour. I would also go 20", you can always cut 2" later...

I think I have finally decided to go with the 358 win. I will be shooting only factory ammo in the 200-225 grain range. What twist do I need to go with?

I would go with the 12 twist.