That seems to be a big buck rig there.
The PSI Big Air is probably the most well thought out carb on the market. They are not cheap by any means.
They will tune easily and give the 145 everything it wants from a naturally aspirated engine.
IF you want a "well designed" exhaust system, your not going to look at any 2 into 2 systems for that beast.
I'm not sure how you are with asthetics but, I would give either RB racing or JBV racing a call.
They will produce a system for you that will do great things.