I see what you are saying about the outer cv joint being the weakest at those 2gr power level. I have the v6 or st185 outer with 26 spline.
It depends on the outer cv joint you are using (more like which wheel bearing you want to use for the rear). Here is a plan I have for my 5x114 bbk. This is not cost effective either way.
I would:
1. Make a wheel hub for the rear for 5x114 w/ bbk, wilwood caliper w/ ebrake, better wheel selection
1a. Use the spyder wheel bearing and machine a wheel hub to fit
1aa. This is due to the abs sensor, as I know it, the abs works fairly well on the track unlike the sw20, some folks take out the abs fuse at the track on the sw20
1aaa.
Note: I have seen the rear knuckle (w/e you call it, the whole hub) machined to accept a sw20 wheel bearing, sw20 wheel hub, and spacer for abs, using the toyota 30 spline outer cv joint aka turbo outer. BBK is built around this.
1bbb. To keep the ebrake, use the wilwood caliper w/ ebrake. As far as I know, no other toyota use the spyder ebrake from looking at the camry, rav4, avalon, fj cruiser and tundra.
1ccc. Keep the spyder rear caliper, make a two piece rotor to fit. Keep in mind that I have seen no aftermarket rotors with a .63" thickness. This would automatic be out of the picture.
2. Front, wilwood caliper 6 pot, make a new knuckle to accept a camry rear wheel bearing, 5x114. The sensor looks the same thus far. Build your bbk around this. I have seen many online examples from the 240sx. Up to the imaginations.
2a. There may be an easier way to install a 5x100 setup but it would be a waste of time.
2b. There have been twice I have seen the toyota knuckle broke from changing wheel bearing. They are strong but unbreakable they are not.
Hope this help you in your decision.
I am not sure what exactly you mean as the main problem is the size of splined shaft going through the hub. It is too small and breaks easily. The turbo axle does not fit the standard hub so modifications are required. As far as I could gather the turbo axle and Camry V6 is similar.
At this stage I am considering one of the following:
1 - use Camry v6 hub with Xtrail bearing and machine the upright out 2mm to fit. I then convert front and rear to 5x114 pcd.
2 - machine a hub from special material using the Camry v6 as model and make od of the hub 3 mm smaller. Then stay with 4x100 pcd all round.
3 - machine original Camry v6 hub od down by 3mm. This is not likely to happen as I do not trust the strength of the hub of 5mm wall thickness in standard materials.
4 - use standard hub with upgraded axles = not really an option as it will break.
5 - use MWR hubs with aftermarket axles. Not a viable option for various reasons.