Need help building this bike:)

Hello all,

I am currently thinking of turning my beloved bike into a gravel/touring bike. The bike is a steel frame Aarios from the late 90s. I would like to put drop bars and change the transmission. Along with those elements I'd probably also change the wheels and tires. For the gears I was thinking of getting the campagnolo centaur 11 speed groupset although idk if they are compatible with my current wheels. I have no clue what bars, wheels, and tires to get. My budget is around CHF1500 (I live in switzerland). Along with the images of the bike I also attached a reference photo of a bike that I find quite nice. If there is anyone out there that has any suggestions about the groupset, bars, wheels or tires, or all of the above it would be very greatly appreciated. Lastly I would like to say that I have very little experience with bike building so I am also debating whether I build the bike myself or if I give it to a bike shop with the parts. Thanks in advance for helping and I wish you all a nice new year full of happy days:)