DS1 (nearly 4) Has a S and S maxirider. DS2 (nearly 2 and 1/2) Has a S and S Meridian. The Meridan needs replacing so my question is do we give Maxirider to DS2 and Buy DS1 something like S and S Hi liner and use a harness with that or do we leave DS1 as is and buy DS2 a Maxirider as well??

He is no where near being the 26kg max for maxirider. But I also see that 26kg is Max for the Hi liner as well so not sure.