As above - unless you are planning to sell the car leave the auto as it is.

You can still mod the car with the auto and the ECU upgrades (hopefully coming soon ) all work with the auto. As for the swap - it is a waste of time and money. The other thing is query whether more than just the transmission needs to be changed to make it work properly. I say this because Honda has assigned a different part number for the ECU depending on whether it is auto or manual. Maybe that means nothing but it makes me wonder whether the maps are different.

The other thing to keep in mind is there is plenty of fun to be had improving the suspension set up - eg with sway bars, etc. Straight line speed is not everything.