The graph in the article was made using a 30m dish, which I would not consider DIY territory. The referenced article is a study on what size dish is required with a RTL-SRD. Their conclusion is a minimum of 6m dish is required with simple post processing. They conclude that with improved hardware and better post processing 3.5m dish should be usable.

I'm thinking phased array. It's a more scalable method to getting large apertures and it can constructed to target multiple pulsars at once.