How should I pick the techonology platform for my website?

We're building a site, which will have to do with a lot of analytics.

To be more specific: - One users could input up to 40 variables - Those variables might be categorized into no more than 3 categories - The system, based on the pre-calculated of all system's input (recalculate every hour), seek to see if the specific user's input is match with the pre-calculated result.

Even more specific: There are 3 users, user A, user B and user C. User A's input: 1 2 3 User B's input: 1 3

The system calculate A and B's input, to give out the result: 1 3

Now, user C input: 2 3 4

The system calculate, and give out the result: 3

Now, if there're 10k+ active users, things will get pretty nasty, right?

More information:

• We are a 3 man team, with a PHP-dev
• The dev have 2 years exp with PHP, joomla, wordpress, to be specific. He does have some expertise with Ruby on Rail, but not that much, I'd say.
• We need to move fast, including getting out the MVP.

Would appreciate any suggestions and advices, thanks in advance. And sorry if my question annoyed you.