Stroller attachment for toddler

...
My parents surprised me a nice stroller set for baby #2 and I don't want to be rude and be like well I had my eye on this other one lol 
but I am wondering if there's some sort of attachment I can add on it to turn it into like the sit and stand double strollers? Would love to be able to go on walks and stuff with both the boys! 
I Might just be dreaming but it sounded nice to be able to just buy a attachment lol