Boie, yes u can install EPS in your khyber. and the same steerng rod od ALTO will be installed. but that would need some slight modifications coz this rod is bolt to bolt fit for ALTO.
For ur second query, preoviusly i changed my santro into power steering about 3 years back and the same process of changing each and every thing (complete assembly line Steering wheel, kunghee, pipe, motor etc. ) was being done. but these days margallas, khyber, cuoure etc are using EPS of alto. So choice is urs coz initial cost will be same for u but EPS is a maintenance free more sophisticated and tension free additions.