Well winter time is here in Colorado. First snow fall expected tomorrow

That means it is time to get to work on my build..
First off when tearing into the block I am looking to get the blower and snout ported.
So for those guys out there who had it done
1. Who did the port job?
2. Would you trust a core exchange(couple shops have ported blowers ready to be shipped on an exchange basis)
3. Gains to be seen? Boost gain/loss?
Thanks in advance!