Heater recommendations

[Qasimja]

So im looking to replace the heaters in my DT i've had them for 3+ years now any recommendations? im using an eshopps RS-200 sump and my tank is 150G 6 foot so about 175-180 total water volume the compartment in the sump the heaters need to fit into is 11"x 11.5

 

[Propane]

I’m using Innovative Marines Helios. So far it seems to be working fine and is easy to use.