I would say he's not L. Because I'm such a dunce, that he'd never ask me to help. Matsuda would be more competent than me. Then I would try to contact the actual L to tell him someone is impersonating him (but if someone was, he'd likely already know).
But if he had sound reasoning, then okay, there must be SOMETHING I can do better than Matsuda. Maybe I'm a better coffee/tea carrier or something... in that case, yes, I would. :D
He'd pay well, secure my old job or provide me with a new one if I couldn't get my old one back once the case was over. We see that he takes care of his people when it's revealed that he had funds set up in case any of the officers on the team lost their jobs (which Watari spoke up about "too soon"). Hell, if he didn't want me on staff for future cases (which would land me in his constant occupation, even between cases), he'd likely see me set up with a BETTER job than what I had before. ^_^ .... (too long a reply? >///>' )
I would leave my current job and join L. Kira aka Light needs to be stopped. L already gave the taskforce's families enough money to last a lifetime. he'll do it for me. without me knowing of course. i'd refuse the money if i did know about.