I will start by saying that a lot of people dont have great luck with aftermarket cams on the 5mge. I duno why, especially considering some of the highly reputable companies that make them, but alot of people have switched only to switch right back to stockers.
Gude is one company, shouldn't be too hard to find.
HKS, but I think they are about impossible to find.
TRD? Have never seen nor heard of one, but surely there is.
I would bet that in order to run the cams proporly you need some additional engine managment to componsate. There are some cheap piggy back systes coming to the market that might it feasable to test with.