The difference between S-LSA and E-LSA on the 5 year rubber replacement is that it is not required (but probably prudent) for E-LSA. But the bigger difference is that with E-LSA you won't have to pay the price for "GENUINE ROTAX" parts.
One major difference is that once you fail the 3rd class medical, you must jump through all kinds of hoops to get it back.
With BasicMed, you don't fail. You simply don't pass. Then you and your Dr. work out a solution and you are good to go.
I would not let a prospective FAA rule change affect a purchase at this time.
Originally the NPRM was to be published in January of this year. It is now July and nothing yet! Even after the process is started it will probably be a minimum of a year and more likely 2 years before anything becomes effective.
The Light-Sport Repairman Inspection Certificate allows you to perform the condition inspection on any Light-Sport aircraft that you own. Each aircraft must be listed on the certificate.