New tank, Clean tank, or Fuel Cell?

Hi gang. Filled my car up yesterday and when i went into the garage this morning was overwhelmed with fumes. Was hoping it was just overspill through the vents but once underneath I noticed a big hillbilly-fixerall glob of something where the filler tube meets to the tank.( see Pic). The leak coming out of the glob is a rust-colored, gelatinous, substance so I figure the tank is probably shot inside. I've never replaced a tank and it's components, but have heard others gripe about it. So my question is should I replace the tank and original components, clean it out and replace some gaskets, or just get a fuel cell? Any advice is greatly appreciated and thanks in advance!