The standard solution is dual licence. Release under GPL, retain the original copyright and when you're ready re-release under some different licence. Profit!
However, if you want to stop people from using your code to provide a commercial service, you will almost certainly need a custom licence. Likely terms will include:
- free for private and non-commercial use
- no rights of redistribution
- no rights of sub-licensing
It's not easy to stop people from making money (if they can). You'll need a lawyer, but you'll also have to be willing to sue people.
I think I'd focus first on making something good enough that people want to steal it, and then making it better but only for your customers.