POR-15 is good stuff, its what I've been using. I've got my entire front clip undercoated with it now and am in the process of doing the entire underside. I am going about it the "overhead" way which isnt too terrible, just dont wear clothes you want to keep, lol.
Luckily my car has no rust (that I've found yet) so we're on track. I'll have a rotiserie like end result with all the extra hours of manual labor
Its nice though - you'll thank yourself when you're done. I plan to keep my FC for the next 50 years so yea... take the time now...