As others say, a K03 would be way too small for our engine, I would recommend a PrecisionTurbo 5858 or if you have the money, to look for a Xona Turbo.
I wouldn't recommend the hans turbo kit...
For the exhaust manifold, I would recommand one from BlueWater Performance, the quality / price ratio is good, but if you want the top quality, I would recommend the JDL top mount, it's not listed on their website anymore, but you can contact them and get one. If you are looking for a cheap option, I would recommend the SPATurbo exhaust manifold, I have a few setups using this one.
As for injectors, 550cc seems good to me and I would recommend an high-pressure fuel pump such as a Walbro (they are cheap and good quality) or a Bosch.
For the intercooler, Vibrant Performance have good price. For the tune, UnitedMotorsport seems to be the best on the market.
If you want to get the best from your turbo, I would get an IE intake manifold, for the mounts I would wait to see if they support the turbo setup well. If you do a turbo setup, you should upgrade your clutch, I know someone that didn't changed his clutch when going turbo and it slips and slips... Keep in mind that the differential is weak on the 5-speed and maybe you could look for a LSD or a 02Q swap.
Then, for the power pulley, the harmonic balancer sucks, the pulley is just lighter... I would recommend a TTRS pulley, the harmonic balance is better and I have been told that it would give about 13whp.
The rod isn't really the issue, our rods are like the 1.8T rod, they handle boost pretty well, our pistons are a bit weaker. At 10-12psi, I would't mind about upgrade pistons / rods, some people run 14psi with stock internal without having issues. The head spacer is good to reduce the compression, but I have been told our engine runs on low-compression already.
Good luck with this project, I also wanted to turbo mine in the past, but now I'm more interested in Quattro for the winter and also because all my friends have subaru and AWD is amazing ! Maybe a Audi URS4 ^^
Have fun !