Philips norelco Body groomer 5000 with back attachement or 7000 no attachement?

these two products

Very conflicted on which to get. Doesnt seem to be any other brand or company that sells a body groomer with a back attachment or many who sell a shaver for the back. There is one giant razor but idk if thats a good idea?

Im reading the 7000 norelco is one of the best for body grooming..however i dont understand why this one doesn't come with a back attachment? Is it maybe not possible to use with one?

Or since i would like to groom/clean shave my back should i just go with the second best option of 5000 with back attachement?

Options are i suppose 7000 and get someone to use it on my back or 5000 with the back attachement

Any insights? Thanks!