Sodium and potassium perchlorate are still good oxidizers

For lots of hobbiest ammonium perchlorate is hard to come by and potassium nitrate is not strong enough so I suggest you try 61KE: 37.8% 50μm 23.2% 400μm Sodium perchlorate

7% Ammonium perchlorate( could be replaced by potassium nitrate but it could affect isp)

12% nanoparticle aluminum

1.25% Graphite

2% Potassium ferrocyanide (K4Fe(CN)6)

1% Copper(II) oxide

15.75% Polyurethane binder. To help with pour ability you could remove 1% from the NaClO4 and 0.5% from aluminium and add it to polyurethane This chemical are relatively easy to buy or with basic understanding of chemistry make and the expected isp is in the range of 185~200 at sea level depending on how you modify it