Long curly red hair Color question

Hi,
I have long naturally curly hair, which a few months ago I dyed red with a permanant Clairol color. A little carroty for my taste, makes me look too pale, so I want to go with a cooler red. Is that possible?
Also, the red fades so fast and everytime I recolor my roots, I need to reapply to the rest of my hair too and isn't that going to kill my hair over time?
I've been coloring at home with a friend who colors her own hair red all the time, permanantly, and doesn't seem to have a condition problem, but I'm afraid I'll have a head of straw after a while.
Is a pro the answer? How do you know if they're good? i have a friend who's been doing hair for 30 years and I trust him to do a good job, but what should he be doing so when he suggests something I know whether to say OK, or no way?
Thanks!
Sally