I use wheel bearing grease but any light grease should work, if you live up North and plan on working the top when its really cold you will want to use a very light grease, it is very important to keep everything well lubed spare parts are hard to come by and expensive when you find them.
I would not operated the top till all the gear boxes and drive cables were lubed, I use 80-90 gear oil on my drive cables but you may want to use something lighter if you are in a colder climate.
If your handy you can even take the motors apart and clean and lube them, once you have done all the cleaning and lubing you should be good for several years unless you operated the top a lot.
I lube the screw drives once a year with gear oil other than that I don't anything, the Retractable that I have had for over 20 years still had good clean grease in the gear boxes when I checked them after almost 20 years so they go along time before needing
to be serviced.