I maintain mine only with new genuine parts mostly, so cant tell much about aftermarket parts availability. In Karachi, Nasir motors is the only authentic place which still stocks Honda genuine parts for older models. Honda sugoi keeps some maintainance parts, mostly out of stock for this model.
As far as regular maintainane is concerned (genuine fluids and filters), thats not an issue.
Genuine engine maintainance parts like seals and gaskets, timing belt, tensioner, water pump, oil pump etc are also available.
I also recently performed coolant replacement, replaced all rubber hoses (radiator, iacv, heater core), T valve gasket with new genuine parts.
Genuine suspension parts like Shocks, balljoints and bushings are availble.
Body parts like bumpers, windshield+gasket, moldings, monograms etc are all available as genuine too.
Interior trims like handles, moldings, rear view mirror+its roof trim etc available new genuine aswell.
Above is whatever that has been recently put in my car, there will be many more things done in past.
The parts have not exactly been cheap but thats how it is with genuine parts. Kabuli parts are available aswell for this model.