Well, just about anything is possible, including swapping an ABS system into an older 240. Partial list of what you'll need:

ABS sensors for front wheels
ABS servo
ABS front calipers
ABS rear calipers
Front strut towers with ABS sensor mounts and dust covers (backing plates)
Differential with ABS tone ring (basically, the whole rear axle from an ABS-equipped 240)
Possibly an ABS speedo

I'm sure I'm leaving a lot of stuff out.

FWIW, you'll find a fair number of folks here who are not convinced that ABS solves a lot of problems. A changeover of ABS brakes would be asn undertaking of a magnitude on the order of swapping out an auto trans for a stick shift, I think... kinda "skill level 3+".

If you skidded on uniform pavement and your skid moved your car in an unpredictable direction, it could be that you have some worn tires, brakes or suspension components, or a front alignment that's out of whack.
--
Thank goodness we don't get all the government we pay for. -- Will Rogers