Since I do not do software this info might work differently with you, however...

I'd say grab about 5-10 people out of forums (such as this one) and have them test your stuff for free. These will be your testimonials.

You can then work on your landing page via PPC/traffic exchanges/what have you and see how it converts.

To increase conversions I've found the whole Mass Control idea of lots of cool free stuff ramps it up considerably. In fact, by making MC style changes on my site I changed my .5% conversions into 10% and 35%. No, I'm not kidding.

- Relate to your visitors
- Give them cool free 'original' stuff
- Soft sell aka what you give is great, but it's only part of the story.

Get some testers, then pre-warm your traffic before you even show them your sales page. Getting people interested in what you do and sell before your try to sell them stuff is massive.