Just a point of clarificationn that ocurred to me - the challenge as set suggests that you must stick with one team but that is not essential. I see no reason why you couldn't change jobs if you wanted to, but within the following restrictions.
1. You must achieve at least one promotion with your original team.
2. You can only accept a job that is offered (so you can't apply, you have to wait for an offer).
3. You must immediately implement the squad restrictions for your chosen path.
This should allow you to take up a position at a bigger club once you have established something of a reputation but the need to meet the squad restrictions immediately could create some interesting scenarios.