What leads you to believe it is not sufficient?
I think that having a working *manual* pump is mandatory. If the boat floods, you might lose your electrical system. I have 2 manual pumps, one in the stock location in the cockpit, and one below deck, mounted in the Settee forward of the galley sink. Not many people add the second pump, but offshore racing rules require it. The manual diaphragm pump on my boat was a Whale Gusher 10. They are very expensive and easily rebuildable. I am not sure if the 384 had them, but it is a shame you don't have it.
A single decent sized rule (2000 GPH or more) is otherwise probably enough. Some people add a "maintenance" pump in addition to this, a small 200-550 GPH pump that is able to get the last little bit of water the big pump can't. The big pump would then hopefully never activate. Be sure to de-rate the pump substantially for the lift to the discharge. Some people have a second big pump at a higher level in the bilge.
The rule float switches are *not* ok. They will fail, and fail again, and never work when you need them to. I have used both a Groco Bilge Pump switch, and a jabsco switch that I like. Both work on hydrostatic pressure, and have no moving parts or electronics in the bilge. I like them both. I am sure others will chime in with what they like. Any quality switch is fine as long as it is not one of those cheap lever type switches that are so common.
Jabsco Hydro Air Bilge Switch | Defender Marine
Groco Bilge Pump Control Kit | Defender Marine
Have reasonable expectations of the pump. If a hose breaks on a 1 1/2" through hull, no bilge pump will keep up. The point of the pump is just to buy you some time to find the source and deal with it, and drain the boat afterwards. Spend more effort maintaining through hulls and changing hoses than replacing and adding pumps. Unless it has been done by the previous owners, the hoses are old enough that they should be replaced.