As an amateur, not-making-a-dime web site maker you probably don't need the full 22-font version of Helvetica with support for Greek and Cyrillic. The Standard OpenType version is $29 a font.

I'm very sorry the site's not live right now so you can see that very few fonts made with FontStruct can be replacements for commercial fonts. It's a tool for creating modular typefaces -- a very specific genre of type design.