I would say go ahead and get the ebay flywheel and clutch (if those are the things you need to get your car going). Ebay do have some good deals from USA at the moment.

You would be buying it mostly for the lightweight flywheel. I have ordered something similar. It will give better acceleration, good for circuit and some hillclimb tracks. (I have seen a light flywheel cause missed gears and lost momentum on a tight hillclimb course). For casual drifting, the light flywheel may make things worse. So decide if that's what you want, or just swap it out later. The F1 Racing brand is not known to use, but its solid alloy steel so I can't be too bad.

A normal style clutch is OK, that is what I run. For a non-turbo setup I'm fine with spending money everywhere else and running a stock clutch. Maybe for drift you want a good clutch and old tyres, and stock flywheel.