Twin/tandem for different ages?

[hoover1234]

Hi all just wondering about some recommendations for a twin or tandem pushchair for my LO's. DD is 1 and we are expecting a new arrival in September.
Also just like to say really cannot afford to go over £4/500 so I know my options may be limited
tia

Oyster max is good, and it's an alright single too, second hand donkey as well?

Out n about nipper double - brilliant buggy