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.
Agree on phased array as a good option to get necessary aperature.
My thinking on the better hardware was that getting 10Mhz bandwidth allowed them to reduce the dish size to 3.5m. Better dynamic range and even more bandwidth might get you to <3m, which could possibly be in old C-band dish antenna range.
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.