To replace with 'proper' pipes you will need to drop the fuel tank, which can be a pain in the rear, then, unless the fuel pump is new, you will have to wrestle with rusted on unions, break the pump outlets, buy a new pump and then start again.
My suggestion is that you use what you have, the copper/rubber pipe is more than up to the job, however, as you point out there should be a fuel filter in the pressure line bolted to the chassis in front of the drivers side rear wheel, when I replaced all my pipe work I just got a standard push fit with clips filter off ebay, larger capacity than the stock rangie one and held it with a big jubilee through a plate I pop riveted to the underside of the floor. This was mainly due to the fuel filter bracket crumbling before my eyes when I went to remove the old filter.....