The way the tap works, you tap on the line side of the fused device within 10’ (max line side conductor length when applying the 10’ tap rule). The load side can be as long as you’d like (given physical limitations of things like voltage drop - the conductor is protected by an overcurrent protection device). Finally, the 65kaic is only if your utility is capable of providing that kind of fault current (for a very limited time) if a bolted fault occurs (dead, quick short). There is almost a 0% chance, in a residential situation, of this kind of fault current being available at the terminals of your panelboard under any kind of fault condition. Also, a bit of a dirty secret in the industry, at small breaker sizes, there is not likely much difference in manufactured circuit breakers other than one line was tested to the higher fault values. At bigger sizes, there are major difference. For example, a 2000A bolted pressure fused switch is made to handle 100kaic and applies pressure to the contacts to ensure its withstand rating.
Good luck to you. I’m sure your choices will work our great.