Would the Evo turbo fit on the manifold?
If you want to go different, there are plenty of turbos that bolt straight on and will be supported by APR.
I doubt APR do an "off the shelf" map for a K03 GTI with an Evo's turbo bolted on, you would probably have to go for a custom map.
Using your K03's map with a boost controller just wouldn't work properly, the spool characteristics would be well out for starters.
I like your thinking with going for something different, but it would be a right PITA