Ya a port and polish is a great idea, you could do it yourself if you have the port and polish kit and a good eye, or you could send it off to a machine shop..
Kibblewhite springs and valves are a good idea if you are using a hardfaced cam
but i here if you are using any hotcam you can use stock valves and springs (that is if yours are in good condition )
It all really depends on what your motor set up is going to be
2003 TRX400EX
Red/Orange powdercoated frame--Full Yoshimura Exhaust ((Titanium Header Wrap)) --450R front shocks--+1 CFM Aluminum Oil Tank--Aluminum Oil Cooler--SS braided Lines--5.2" Spal Fan--CFM Aluminum Airbox--Uni Air Filter--DG Nerfs--Pro Taper Handle Bar
Still in progress of ground up build