Poly steps is a good choice, but you launch in to the channel and its a lot easier with 2 people. For a change of scenery try Torquay harbour as there is some great coastline on the way around to Teignmouth and Exmouth.
Torquay can be launched at all tide, double width and pontoon nearby, trailer parking on the harbourside, and pay and display car park close by. So its easy to launch on your own, but also family friendly.
Can get a bitty busy when sailing events are on.
PS I'm pretty sure you can get it in at Topsham, and there is definitely one place that does a crane launch, just google for it.