Flash Advice Needed

Apologies if this topic has been covered to death already (i have searched) and apologies if this is in the wrong forum but i thought it'd attract more attention from the right guys here. If any of you have moved from Canon to Nikon you may be able to help most.

I'm currently a Canon shooter (30D) and i use a Canon Speedlite 580EX II. I'm looking to move to Nikon. I want to know what's the Nikon equivalent speedlite? I was thinking of getting an SB700 - or should i get a 910? Are there any other non-Nikon speedlites i should consider?

Please note i need something of the 580EX II's ability as i own a 430 too and that doesn't cycle quick enough for my needs.

Also, whats the transition like moving from Canon to Nikon? Do the flash systems work in essentially the same way? This is an important factor to me.

Any advice is much appreciated.

Thanks,

Manny