If priiloader doesn't start by holding down the reset button while booting up your wii and you don't have bootmii then you're pretty much out of luck.
As to modchips that can fix bricks: The only one I know that can do this is the infectus chip. But this a form af Nand programming and that is above my head.
You might want to check out the following threads:
I hope this helps you on your way of geting your Wii fixed.