MOT today, Phew! & spring dilema

[tuttle]

Little car, as it's affectionately known, aced it's MOT today. Bar one thing. Rear, Pass' spring is corroded. So I shall be replacing the rear pair.
But which springs? OE or same height aftermarket? I don't want lowering springs, I'm really happy with the handling as it is, & feel they may probably upset this?

Can't stretch to coilovers at present