Considering how many Toyota models use the 2GR-FE's, it does not look good for us as one would think there would be more power options out there. The engine has been around since 2005 and according to Wiki its been in 21 different Toyota models not counting our Evora. Only one very limited production Toyota model received the 2GR-FZE (2007 TRD Aurion, the Evora S setup), which means Toyota probably decided that it would not be feasible to provide a model with this engine in larger production numbers. This decision may have been based on potential warranty claims, cost of production etc. The SC was also built by a Austrian Tuner who for some unknown reason does not sell the SC for the engine (Maybe per contract with TRD). TRD also does not sell the SC for this engine. The SC upgrade kit is available through Lotus Sport in the US though as an off road use limited warranty kit. Also there has been very few news of a running Turbo 2GR-FE. The only one that I can find was a Camry who has been working on the project for over a year and still has trouble getting it to run correctly. There was some chat about a monster 2GR-FE sometime ago but it sounded more like a very expensive custom built engine for off road racing. Lastly, the N/A Cosworth built setup is in the 100K range, not 50K. The Racing Evora is also very different from the road going car so it's characteristics may not be favorable in a road going car.
So what am I really getting at is that if this was an easy engine to work on, we would already have lots of options. If you want power beyond a S, its going to take pioneers willing to sacrifice several 2GR-FE before we will get a good cost effective and reliable solution. I think for now, the best option would be to get the SC kit from Lotus Sport with the ECU, Clutch and flywheel for those running an N/A. It's a very expensive SC kit. If you are running an Evora S, I would just keep it stock. Toyota probably did their homework and passed the info to Lotus on what the possible failure rates are for the setup.