I can't comment on the stuff linked as I haven't experienced it, hopefully someone has and can advise. Maybe pop over to talkaudio and see what they say.
There's a guy on there ('loudboy') that sells some top stuff.
From personal experience flashing tape is a complete waste of time and money. Takes 100 times longer to remove when you realise it does nothing but add weight. I'd recommend silent coat all day long.
Cheers