Quick answer
For most users, CoinSpot is the direct Coinstash upgrade. Nearly as many coins (490+ vs 1,100+) but with a much larger user base, 12+ years operating history, publicly disclosed ISO 27001 and Mazars proof-of-reserves audits, and 24/7 Australian-based live chat that Coinstash's email-only support can't match.
If wide coin selection was your main reason for choosing Coinstash, CoinSpot at 490+ coins covers 95% of what most users need. The 1,100+ Coinstash number is impressive but includes many low-liquidity, high-risk coins most investors shouldn't touch.
For SMSFs, Independent Reserve. Coinstash supports SMSF accounts but doesn't have specialised SMSF tax tooling. Independent Reserve is the industry standard for Australian SMSF crypto investing.