You'd have to define a portal I guess Paul. What makes a good developer is an interesting question?
There's a good article at
seomoz.org/blogdetail.php?ID=1064 which suggests questions you could ask developers at interviews.
If you're looking for developers for a project that really needs the sort of high performance that J2EE brings then perhaps you should hire an IT Project Manager or Analyst first and let then handle recruitment.
Personally I think that good devs have an eye for detail, an inquiring mind, a love of problem solving etc etc
And truly great devs have all of the above plus are good looking, charming and almost certainly have a name that begins with K
