well, with an 03, it wouldn't be all that hard
get a headgasket from the supercharged cavy, and have a shop weld a 4-bolt flange to your downpipe where it used to connect to the cat
an internally wastegated turbo, some post-cat 02 sensor adaptation, some custom pipes (an air to water ic would be easiest in that engine bay), and the cost of a shop to do a fuel map for you, and you'd be set
i gaurantee it could be done for under 2k with a little gt15 or gt20, and however much boost he s/c engine runs, hell you could probably just gank the fuel maps from the s/c'ed model if you used a small enough turbo