Medyo mahirap si pagkasyahin sa budget, but if you are patient enough to do a step by step upgrade, given the existing gears you have, if I were you, i'd start with a good relaible amp like a 4ch- RF Prime. I think 10k fits the budget right there.
Good installers around your area is Kid Audio/DB Audio. If you can travel to Paranaque, Musico will be one of the best and highly recommended installers around.