I live in outskirt of Cambridge.
Fiance visa is to get married in UK within 6 months. NOTHING ELSE!
Spouse visa, you're correct, marry in the Philippines then apply for spouse visa.
You asked, what is the best and easiest way to get a visa. My answer first SPOUSE, second, FIANCE, third VISIT VISA.
I suggest you spend time searching and reading the forum because situation like this has been discussed so many times and you'll understand why spouse visa is the easiest and best to apply to get a visa!
Goodluck!