To build a 2 liter 2T-G, it is a simple recipe with not many options. These are the things you MUST use:
3T block or 2T block modifyed.
3T or 3T-GTE crank (both the same).
2T or 3T conrods (all the same length).
After market 89mm or 88.5mm 3T pistons.
Must use 3T pistons of some sort, not 2T.
The cheap option is to use standard 3T-c pistons (can get 1mm over at 86mm). This will only be a 1.8 liter motor, but still a good thing.
If you want to use 18R-G pistons, you can but you will need to keep the 2T crank I think. This is still a good thing and was common back in the day. They are 88mm giving 1703cc I think. Most people to go with the 3T crank.
Use any cams and valves you want. The 2TG head can easily flow as much as it needs to. Don't stop having idears about how to do stuff differently, but I think you will end up with the above formula for a practical engine.