Will the Yongnuo rf-603 triggers work with nissin di622 mkii?

I have a nissin di622 mkii and I'm looking to purchase a cheap trigger for off camera flash. I'm looking into the Yongnuo rf-603's but there seems no definitive answer as to whether it works with it. I have a Nikon D90 by the way.

They should work with any Nikon compatible flash, but i really can't tell you.

From what i've read in reviews it's a question of luck, and even if they do work some people report a 10-30% fire rate, which is disastrous.
So i suggest staying away from them if you need any kind of reliability.

May i suggest you get the Micnova Wireless Flash Trigger MQ-FT-N instead
It's a bit more expensive but it's sturdier (metal hot shoe not plastic like the 603), and you can get separate receivers if you have more flashes.
This site asks 39 pounds, i can get it for 50 euro (even with 24% tax so you might be able to find it cheaper)
http://www.ukphotodistro.co.uk/micnova-wireless-flash-trigger-set.html

May i also suggest the Hahnel Combi TF (this is proven to work with your flash, but it doesn't get the flash out of stand-by so you will have to turn off the stand by function and you are set)
http://www.hahnel.ie/index.cfm?page=dslrremotecontrols&id=64&pId=64
It's also around 50 euro ($60), separate receivers are also available
I'm not sure of the others but his also works as a remote camera trigger
See here

If buying any of them get it at a reputable store where you can return them if they don't work with your flash or don't work at all.

Cheap stuff on ebay may sound good and promise a lot, but it's very risky, if they don't work you will be stuck with them, because to send them back you will have to pay more then what you bought them for.

You can gamble $30-40 (depending on shipping) or invest $60 (although i've seen them for $70-90 as well)