Hello bigmac, welcome here to the forum.
May I kindly suggest you read this thread
All New Guide - How to apply for a Spouse/Partner Visa
At least it will give you the basics of what's involved and what the costs are likely to be.
In principle it is correct that a sponsor needs to have a minimum income of £18600 (or very significant savings above £16000)
There are a number of ways to evidence the required amount and there are some specific exemptions.
It makes no difference where the marriage actually takes place the key requirements for any visa leading to settlement are the same.
She could apply for another student visa, but this could only be switched to settlement via the requirements indicated in the above linked thread.
At least this route would allow her to have limited employment, which when combined with any employment income you could also secure just might achieve the required minimum.
Unfortunately the income requirements need to be maintained and proven at visa application, then after a further 30 months at ILR (settlement)
One other option would be for you to consider moving to the Philippines.
I have to say that would be a huge decision for you to consider and one that would mean putting all your trust and faith in this lady.
Sometimes life throws us a curved ball.
Hope you'll stay around. Make new friends, and maybe see another great idea/opportunity.
BTW, Graham does make a very valid and important point.