Compression numbers and spark plug recommendations

[Tyler Clark]

Did a compression check with a cheapo Harbor Freight compression tester and
got the following numbers:

Note- the engine was cold so I'm wondering how much different the numbers
would be on a warmed up motor. That's what the FSM recommends. This is a JDM
SR20DE with a T25 bolted to it. I run about 9.5 pounds of boost.

Cylinder 1,2,4- 130
Cylinder 3- 122

These seem a little low but like I said the car was cold when I did the test
and I don't know how reliable the tool is either. I'm also running a small
Hawker battery so maybe the RPM's are a little low, could this skew the
numbers to be a little lower?

Lastly what plug are most of you running in your turbo cars? What gap are
you setting them to?

Thanks in advance!