If no one has done it yet: Welcome to ProCooling!
The Johnson pump has 3/4 OD connections (that's right, 3/4, not 3/8), unless you're talking about another Johnson pump than the one in my sig. It's not an ideal choice for a quiet system: it's got a little bit of a whir.
Your idle temps should be a bit lower, but you'll see a great improvement when you turn up the heat.
As for the airtrap, see my sig, or check out V12|V12's thread on airtrap design
here.
Good luck!