The first thing I would do is wait. In the next few moths you will see a number of parts coming up for sale that will be more accurate than anything previously offered. However, if you want to have the saber now, then I would get your parts from Roman's Empire.
But be aware that within a month, Prop Runner and Serifino will be offering the most accurate parts yet and they will be produced in steel.
I would order a replica booster and emmiter(coming soon) from Prop Runner and Serifino; a replica pommel from Roman's Empire; and a graflex clamp from either Roman, Parks, or e-bay.
As to the grenade, the two now available Roman's and Parks' both have their pros and cons. Romans are more accurate in size and shape, but Park's are made from more accurate materials (steel rather than aluminum). If I had to choose between the two I would go with Roman, his grenades look pretty good, the only problem is taht since they are aluminum, you cannot weather them like you would with steel. Also, Roman is a good guy to deal with.
Also, be aware that there may be a run of new more accurate steel greandes from Serifino in the future, but that might be a long wait (he still has to make us boosters and emmiters
)
Hope that helps.
Dan Stokes
DDStokes@aol.com