The Pro-guard 7 has more surface area and will help a little on free breathing.
The V6 air box mod will help keep out the rain when you are having a strong rain, when filters get wet, they don't flow air very well.
ORM/SEGR will help a lot by shutting off the EGR valve and upping the oxygen level in the air intake. Just unplug the MAF on the top of the air filter and ignore the CEL until you can get the SEGR installed. The diesel knock will be a little louder, but then you won't have to worry about running into wildlife as much when you are on the back roads. I love watching the Canada Geese run from my CRD and just block the road for the gassers
Fuel cooler will help in hot weather when the fuel temp goes up and the ECM cuts back on the FUEL. If your Hubbies Cummins has the Common Rail injection system this will help his as well.
Since you live in LA, unplug the fuel heater and don't plug it in until you go North of the Mason Dixon line in the sub zero Winter.
I have done the mods I listed and a few more on my signature. With the stock muffler I can be through the intersection before a big Block Taho can even get to the middle. When the road is wet, I slip my CRD into part time 4X4 and laugh as I watch them sit and spin. I can blow away Gasser Liberty's too. CRD torque is great

Train your foot to make the most of it.
Is the Magnaflo (I prefer Stainless Steel) on my list, yes, but the Red Head has stuff on her list too. To be very honest, the restriction is more of a problem when the boost is up for trailer towing than commuting to and from the airports.
Air in the fuel line can cause a little stumble too (before it dies from air in the fuel), lift pump is the permanent fix.
Steve