Quitting ISP to be network admin in a mid-size business

Hi,

I've been working as a network analyst for a big ISP for two years now and the work has been boring as hell, and my growth was super slow (I'd say I've shrunk). I've been sent as a consultant for a mid size company to help them with their network. They are looking to hire a CCNA/CCNP level guy. I've learned so much here is the few months that I've been working that I'm thinking about quitting the large ISP and asking them if I can stay here. Is that a smart move? I only have a CCNA, (working to pass my CCNP Switch in 3 weeks). I'm afraid that this can be risky because if they fire me after 1 or 2 months, I'll have a hard time finding a job with a CCNA. Should I stay with the ISP?

I'm also afraid that since my knowledge isn't so great, that I won't know the new technologies and won't how what nice upgrades can the network have. So the work here also will become boring.