Double buggy and tandems vs pram and sling? Help!

Hi...

Me and my husband are adopting and are being considered for young siblings. My question is,  I don't know what to do about a pram?? We have a small budget and km not a big fan of tandems. Do I get a double buggy or shall I get a single pram and a baby carrier? Youngest is under 1yr and I'm thinking it could be good for attachment too?? Please help!