These are different right? I believe you can get the Mach 1 S/S for $155 while the HP S/S cost over $300, correct? Are the Tokico HP worth the extra $$$ ?
If you have $470 to spend, I'd get Bilstein shocks/struts from ebay. They normally retail for $630. They are great shocks/struts and you'll feel the difference (read the reviews section), and you'll never have to replace these for the life of the car. They retain their performance regardless of age, and Bilstein backs it up with a lifetime warranty.