Actually, you do have another very good option for single-lever two-station controls. Kobelt offers their 2090 Series which synchronize the master and remote levers with chains and sprockets connected by low-friction cables. They are available in two configurations.
The single-engine, single-lever, two-station control system consists of a 2091 master and a 2093 remote. You would need one set 2091/2093 set for each engine. These are best where you already have controls on either side of the helm/wheel, or if you prefer to back the boat by facing aft with engine/gear controls in each hand. The levers and graduated scales can be reversed (left/right) as required by your installation.
The twin-engine, single-lever, two-station control system consists of a 2092 Master and a 2094 Remote. You only need one 2092/2094 set to control both engines from both stations
In either configuration, the ability to advance the throttles in neutral is only available on the master controls, not the remotes.
These are very high quality systems without all of the complication of the Teleflex/Morse switch boxes. They are however a bit pricey.