I seem to have a lot of play in this shifter before it moves the reverse gate or carb. I was told a floor mount foot throttle would work wonders for me but I have a sleek craft executive and the seat are just too high. Would thos billet shifter work better then one I have now. Not looking to spend a lot of money $130 tops.
That appears to be a Morse Controls shifter. My experience has been that they are well made and have very little play or slop in the mechanism. If you are experience a lot play, first I would check to make sure all the plates and arms are securely attached to the back side of the shifter. Then take a moment to understand the sequence of what happens when you move the lever. From a "neutral" position, your gate should be partially covering the nozzle. As you move the lever forward you should almost instantly start moving the gate. Once the gat is in the forward position then the throttle will start to move the throttle cable. Seems like a lot of motion for the shift sometimes but it is probably normal.
If everything is tight and you don't feel or see play in the throttle mechanism itself, then the lag or play is likely a result of long cables, especially if they have a lot of bends in them.
That billet shifter you show will only shift the jet (gate open to closed) and will not control the throttle. You already stated that a foot throttle won't work for you, so that means you would need a shifter and a throttle. You might find something similar to the billet shifter with two levers, but otherwise you are back to a combination unit like you already have.
Do yourself a favor and figure out where the "play" is and work from there.
That looks like it is working exactly as designed. The first movement of the lever is moving the bucket up & down. It is not until the bucket is moved that the throttle should pick up. Adjust the bucket so it is all the way open right before the throttle picks up. Make sure the throttle is all the way open when the lever is all the way forward. Verify the throttle comes back to idle when the bucket is closing. If those events are happening then call it good and go to the lake.