For your laptop:

In addition to the software described above (NutExtender v2.1 and DobroStrings v6.0), I would suggest a straight bridge slide, as the Yamaha will have a curved one to almost match the camber of the fingerboard. You could get that from Elderly (Flatbridge v3.0?). The Dobro strings are not really necessary as long as you realise that the major difference is that the fifth string is slightly lighter than in a normal set. You will probably want a steel bar as well. For this style of playing you really want an old-style one with a pointy end, rather than a modern one with a rounded end, which is really more suitable for pedal steel work.