My parva doesn't grow taller than 20mm, but it also doesn't realy make a lot of runners. It just is latently present, not realy growing not realy dying. Tho of course it grew a bit made a few runners, but for the 18 months it is, it's barely noticeable with te naked eye.. In this condition and its low metabolism it's also very susceptible to get dirty with algae of all kind.. But this is all very low light and no co2.
Depending on the tank size and the scale you like to create in the scape i would say from what i see how it grows in my condition
Even a crypt wendtii can be a very nice carpeting plant.. In my tank i stays very flat to the substrate with a 8 to 10 cm diameter rosette not taller 4 cm high. It's the best spreading crypt in my tank, started 18 months ago with 1 sneak in baby plant and today i have 5 mature ones and keeps making runners.
180x60x60 is quite a large tank depending on your scape scale you could easily go for a larger plant than the usual nano forground carpet plants. CArpet is not the plant sp. is the way you make it grow. As you say you don't like to trim that often, if it were me, i definitively would not go for a HC, MC or grassy type of plant. Trimming a 180 cm carpet is quit a challange and wont be realy low maintenance.
As Tim says, the balancing act, finding the right combination of plants, light intensity and co2. And it is very hard to predict what results you will have, because also water parameters, substrate choice and fert regime all will have effect on how a plant developes.