Default and the most simple one to use is LDK. (Alby runs an optimized Esplora server so it's not depending on blockstream's public server) Out of the box everything should just work If you already have an Umbrel, Start9, RaspiBlitz, or some LND setup then LND is a good option. You need to take care of your LND node then PhoenixD has the advantage to use Acinq's LSP the rest I would not recommend much at this point actually. Ecash is fun.