Unfortunately, I can't help you much here.
Firstly, I'm not aware of SEO/PPC domain. Secondly, I've done very little (and very long time back) work in PHP. I just hit a random internet search and saw that there was much more info available for SEO in PHP (than SEO in Java)
Further, I'm not having my own business (and not planning for it). But a general pattern
is like this: If you want to open a business, start working as a normal employee in a company (maybe startup - so that you can have a richer experience). After working there for a while (this can be from 2 years to over 6 years), when you think that you are ready for the big move, leave your job and go for the business.
However, you'll have to make sure that you need to be a businessman
to start a business (that is - you need to have basic skills - ideas, patience, business networking and so on). Also, it is very challenging thing - you may see that you are earning much less and working much more in business than in job (of course, this will be during initial period - once the business settles down, you'll be in much better position).
Last, but not least - go for your own business only after understanding the risks and if you are willing to accept the consequences. No doubt, if you have a passion for business, all those risks/troubles are absolutely worth it - not everybody has the guts to do something like that.
All the Best!