Most Graflex clamps and bubbles you see on eBay are Parks, and they are not the very best. I do not know of any other current maker of parts, except for Blast-Tech - which only does the calculator bubbles.
Roman's Empire made many good parts, but has closed shop.
Right before Roman's Empire closed, he sold Obi-Wan sabers as kits for a reduced price, and quite a few people bought them. Because of this, I think that there is a pretty good chance of getting a complete Roman's saber with all his latest parts.
Best Graflex Clamp: Roman's Empire. There have even been limited runs of chromed clamps and clamps without the "GRAFLEX" letters. Did cost $30.
Best Emitter: Roman's Empire. His last version. Aluminum or chromed. No other emitter (yet for sale) has been based on the real part. I believe it cost around $45.
Second best was the Serafino/Obee1 which was made right before the discovery of the real part - this one was steel, and hade the correct outer dimensions but the walls were thin. The price of a new one was initially fairly high, but they dropped in price.
Best calculator bubbles: Blast-Tech. Still exists.
There has been a maker called "JediShack", and a few more may have done it too in small runs. All were cast in clear plastic, but not the same type of plastic as the original.
Pommel/Handwheel: Roman's last one should be quite common. Around $45 I think, made from chromed aluminum. Also offered unchromed.
A builder has made a couple of accurate handwheels in stainless steel and sold on the board.
Next best was Roman's last pre-discovery handwheel, which was solid and does not fit together with a real booster.
Booster: Serafino's. The ones he sold in his run cost $81 + s/h if I am not mistaken, but a bit more if you wanted one afterwards. Black-oxidized steel.
Next best is Roman's, also based on a real one, but not exactly like the booster used on the prop. This one was aluminum, offered untreated, black-anodized or weathered. Price around $55 I think.
Next is Roman's last pre-discovery "gear" ... in a special edition accurized by Serafino.
Grenade: All-round, I would say Chen's. There is one in the Junkyard right now.
Price around $260 new. Frag body made from steel. Two versions, one with symmetrical lengthwise grooves, one with asymmetrical grooves.
Next best: Roman's Empire. Aluminum frag body - which was available anodized in black or brown, weathered with blackening agent or raw metal.
A bronze/brass-cast 'nade has been made, which has a more accurate brass stem than any other, but I think the frag body has somewhat rounded edges.
Parks frag body is the only other one made from steel and has correct internal threads, but the stem and wind vane is less accurate, as are some edges on the outside.
Transistors: Stormpath is the most recent maker. His were threaded to fit either Roman's or Parks clamp spacer (you had your pick). There was someone a few years ago who had also made plated transistors, but with a slightly different washer, but I can't remember who it was. I don't think there has been concensus on the exact shape of the washers, as the real transistors and washers are still undiscovered.
There has also been a run of decals for the transistor faces.
