The best way to clean your injectors is to send them out for ultrasonic cleaning & flow testing.
I can personally vouch for this company ...
http://www.witchhunter.com/
As far as anything that you can accomplish through porting the various intake components, ported runners may provide some benefit, but turbulent flow in the plenum and around the throttle body isn't causing any problem.
When you've improved the flow capability of the heads, installed a better camshaft, and eliminated the restrictive L98 exhaust system, then you might get some measureable benefit from porting the runners.
Give your car a solid tune, run a baseline dyno, and then start the mods. THEN you'll know what worked (and perhaps as importantly, what DIDN'T!).
Good Luck!
Steven