You will also need a wrist-pin bearing, and an exhaust donut (the inner pipe seal). I also replace my pipe springs when I do a top-end, but that is just a personal preferance.
As for tools, you should have a micrometer and inner-caliper to check the bore (or you can take it to a shop to be measured), and a set of feeler gauges to measure and adjust the ring end-gap before assembling the engine. It is also a good idea to get a ball-hone, but you can use a scotch-brite pad, as well.
Make sure you disassemble the power valves to check and service them.
I use Weisco's, and have no problems with them. However, with a forged piston, you MUST break it in properly, or there is a high risk of seizing the top-end during break-in.
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1992 KDX 250-FMF porting,two-stage power reeds, Fatty pipe, Power Core silencer,titanium rod,Wiseco Ultra-lite, Pro-Action suspension...Oh my Gawd, they killed Kenny!