Hello, my drivers front side shock is leaking, I have coilovers installed (I never put them on), so does anyone know if it's possible to buy coilovers just for the front? Either that or I buy the original suspension for the whole car, which ever is cheaper

You could get it repaired no doubt or replace the one(s) leaking. If you do the latter you'll need to find the make of the coilovers first. 

Depending on your budget, i'd just get it all on coilovers. You could pick the whole set up reasonably cheap :-)

is it possible to replace the shock absorber on the front ? or do I need a new coilover strut?

New strut