EDIT: secure implementation decided thanks for the help!

Potential alternative option:

. Lightweight app on web which communicates directly to a database.
. Database holds a big list of readily created "receive addresses" by a wallet held off server.
. Off server process runs on my PC continuously checking the database for "work".

This approach is probably a lot safer and would also remove the need for a dedicated server. The downsides would be having to run a PC 24-7 at home which constantly checks for work. The off server process would create more addresses when needed and add them to the database (remotely). It would also send out bitcoins to winners and transfer the bulk of BTC to an offline wallet.

What would you say is the best approach? Regardless of implementation there will be a "hot wallet" and "cold wallet".