[rossriley]

Echoing the other advice, good shoes, get fitted for the first pair at a running shop that analyses you first.

Secondly don't fall into the trap of thinking that you can jump back into running 8km or so daily, you need to build yourself up slowly first, use an easier program like couch to 10k after which you should be in good enough shape to start increasing frequency of runs.

While you're in this phase concentrate on easy paced runs, so hopefully the lungs shouldn't be an issue, you should run at a pace where you can hold a conversation without struggling for breath.