a 1 bar map sensor isn't going to give an accurate enough reading for the pcm to compensate for higher manifold absolute pressure readings. most cars these days will use 2 bar map sensors because 1 bar map's are old technology.
I wouldn't bother changing pushrods unless you need a different length. you aren't going to get more performance out of a different set of pushrods. I would do the 130 lb valve springs instead of the 140's because you want to run the lightest spring to get the job done, and 130 is good for the xp cam. even with that upgraded harmonic balancer you got from zzp, I wouldn't rev that thing higher than 6300 because it isn't going to reduce vibration enough to go much higher. you will get a lot more out of your build if you do a set of ported heads with that xp cam, I recommend the ones that orangeL67 does on here, he doesn't charge near as much as zzp and you get a better product.
as far as boost goes, more is not always better. boost from a supercharger increases the pressure inside the engine, so having low amounts of boost means you have the flow mods set up the way you should. I would do the 2 bar map sensor, and get the tune adjusted, I'm not real sure what would need to be changed, but after that happens if you still have low boost, you might be able to pulley down and then scan for kr
