Definitely go with Jegs if you want a custom all aluminium one. If you want a decent direct-fit aftermarket replacement, get a KOYORAD radiator. I have a Koyorad in my Pathfinder and it works great. It has an aluminium core with plastic upper and lower tanks. The plastic is extremely sturdy and can take heat without issues. I never had a problem with mine. Also, the Taurus fan can be integrated into the Pathfinder shroud for a cleaner look.
Here are the stock radiator measurements from Koyorad.com
As far as rad hoses, they should all be flexible since they are made from rubber.
You can try to give these guys a call too: http://www.sillacooling.com/contact.htm
They can supply all aluminium radiators.