Welcome to the forum (and boating.)
4.5 meter with an 8hp? I don't think you're going to get everything out of that hull that it is capable of.
What is the max hp rating on the data plate on the transom? You probably want at least 75% of that number.
As an aside, I'd get rid of the over-tube tie down (abrasion, eventually), and go with one on either side of the transom straight(ish) down to the trailer, and one or two at the front (one forward, one straight down.) I'd also reconfigure the trailer bow stop to contact the tube, and equip it with a piece of carpeted bunk.
Have fun with the new boat;