check with amihan lumber, they have a bandsaw and planer and will custom mill.
https://goo.gl/maps/95o5c7mk3Hk
i also know a timber buyer in amlan who might help you.
consider coconut slabs if you're going to do raised beds. there's a place in my neighborhood that has slabs dumped on the roadside, i don't know what they're doing with them but there's way too many for one house so i assume they're reselling.
any lumber you buy is probably going to be green and lead heavy. my choice for long term raised beds would be hollow block.