I would use the same filter as long as you want a DE filter, and it worked good with your pool. Keep in mind that whatever filter you select must be able to handle the pump output in GPM ( gal. per min. ) Also after looking at your owners manual , Do you have a base that mounts the pump as well in one unit? If so you may want to use the same filter for ease of installation.
~ I'm happy enough with it I guess. On one site it looks like the EC75 is for a pool my size rather than the ec 65 that I have.
~ I'll have to look to see what the GPM is from the pump. The base does mount the pump. The pump seems to still be working fine so an even swap would be easier. Think this is something I could do by myself, I have at least basic mechanical skills.
I am fairly certain that the EC65 and the EC75 use the same casing (maybe just more /bigger filter fingers), so it should be a direct swap. As I recall installing the EC-75 was trivial, just pull it out of its box and sit it on the base, connect the plumbing and screw in the pressure gauge and add DE through the skimmer. Mine was bought off ebay as a combo set with a 1.5 HP Super Pump, and base plate, I know it is also commonly sold with the 1 HP Super Pump so there is some room for variation, I opted for the 1.5 because it was identical to the previous rusted out pump. The biggest issue you will likely have is your plumbing lines, are they all glued together and have to be cut out, or are there removable fittings to allow the pipes to be removed from the filter?
It is certainly easy enough to change later, so if it were me I would try it first. With removable lines I suspect you could get the whole thing done in 30 minutes or so, a little teflon tape or other thread sealer screw in the pipes and go.