Honestly, save your money because I don't think you'll hear any more with the slinky than you will with just a piece of wire. They are more important for ham operators who need to transmit on a tuned antenna. Additionally, the connectors on your radio won't be compatable.
You won't be missing out with just a piece of wire. Really.
Edit: if you're dying to buy something that will help, think about a simple antenna tuner
Watch how much wire you put on that radio. If memory serves, it's a single conversion set - so you're going to be hearing stuff in places they shouldn't be. Overloading it with too much wire is simply going to make things worse.
As for English schedules, I would highly recommend the NASWA spreadsheet, which I understand now has a separate worksheet for this. It's available from this website. (anything in blue is a link). You will need a program like WinZip to extract the compressed file.