TRF415 MSXX is not in the same class as TA05 ver.2-R. The former has carbon fiber double decks while the latter has carbon-reinforced platic tub. TRF415 MSXX already has all the optional parts while the TA05 ver.2-R only comes about 60% upgrades, you need to shell out at least another $200 (e.g. motor mount, and bulkheads, etc.) to make the car with full options.

If you want to race, get TRF415MSXX, if just for fun, TA05 ver.2-R will do. But don't expect them to have the same level of performance and driving precision.