The 3 speed o-drive has about the same amount of o-drive as the S-10 5-speed. Either will give the desired effect. They are hard to find though & some of the parts are very scarce. Beings you already have a floor shift I would go with the S-10. You can weld your old gearshift lever to it & make it look original. I've done 2 of them & they work great. There is a lot of info. on this website about the conversion.
