I get asked a lot what the best gundog dummy is when starting out. For me personally I would always recommend the basic 1lb or 1/2lb gundog dummy. Not in any fancy colour, although they do come in fancy colours.
for young or small dogs the 1/2lb is perfect, and for more experienced or bigger/older dogs the 1lb is ideal. Don’t over complicate your training, keep it simple. The darker colours help bring out your dogs natural ability to hunt if it’s fallen in longer grass or cover. Although for your marking ability the brighter colours are a good starting point for a novice handler. Being able to mark the dummy is important for handler too, so if you struggle with this aspect choose a brighter colour.
These are fairly inexpensive pieces of equipment, most of them float, but be warned if your dog chews them they do have either sand, sawdust or black little beads in them, something you do not want your dog to ingest. So these are definitely not to be left with your dog. Always monitor them when they have them.