How to find a reliable PHP development company?

I have a task - to prepare tender for contractor to our next project. We need a reliable company which works with PHP & MySQL & JavaScript. It's not so small project and we plan to maintain and add feature every month. So it's quit big deal if you see the long term. So I was thinking how to choose a good company for our project. And I have an Idea which I want to discuss with you.

Cube in orange stock photo by www.pixmac.com

I want to split the tender to 2 rounds:

1. In the first I want to collect basic information through questioner about potential contractors and test communication with them. 
2. In the second I want to invite selected companies from the first round and if they sign the NDA we'll send them a part of documentation and wait for comments and eventually the offers.

What do you think should be in in the questioner? I have tried to design a template for it, so we can improve it and than I can submit in to free templates to google docs. So here it is in Google docs:

• Template for Tender - PHP Development Company

As you see I have split it to 3 steps (actually 4 including the "Thank you step"). In the first I'm trying to get the basic information about company. In the second how they manage their source code and finally in the third how they work.

What's your comments to this questioner?

PS: If you want to compete in our tender send me mail please.