A normal honiong tool you put in a drill should be fine.
Iv just rebuilt mine with new rings head and stem seals and all seems fine. What you should look at is the Oil pressure release valve in the oil pump it is acessable without removing the pump. they tend to stick and cause a constant high oil pressure i found that out on mine when i took it apart.
If you clean it thorily and take off the burrs on the end with a needle file it should work nicely with some fresh clean oil.
And as for the splutter look for an air leak around the injectors and inlet manifold. also look at the EGR blanks and pipework into the manifold :thumbup:
Hope this helps.