Honestly there is no issue using an aluminum control arm. Problem would be the angle if the tip of the control arm (specifically the portion where the ball joint is). I doubt the original control arm would have the correct angle without modifying it. Only way to know would be to try, I'm game so if someone has a control arm they replaced hanging around, I'll through a spherical on it and have a look.
Realistically speaking though, to utilize the spherical roll center corrected ball joint, you would also need to use the roll center corrected tie rod (which requires 17" rims minimum). Now that you're getting into heavy mods, the aluminum probably won't keep up with the stronger steel or chromoly replacements. So you would fab up a tubular steel replacement. Since you're going through all this trouble, might as well convert the inner ball joint to a spherical a well. Since all that work has been done, might as well use the 3 point OEM design and integrate a fully adjustable caster portion into the tubular arm.
Change one thing, 10 more follow, especially when you're messing with something as touchy as roll center correction.