which engraving motor?

Hi everyone,
I have been making jewellery a number of years and i would really like to try my hand at doing some Pave setting and engraving.
I have a foredom SR pendant motor and wondered about buying the hammer handpeice to engrave with? I dont have a huge budget, in fact i only have £150....
can anyone reccomend the tool i need to do this? I have tried push engraving but i find it hurts my hand and i cant get enough control so id like assistance from something! I wanted the foredom power graver but cannot afford it :( Thanks.