Any of the main seal companies should be able to help you there, Chesterton, Flowserve, John Crane.... I tend to go with the larger companies, you have more of a guaranteed quick turn-around, they have more inventory on hand to repair with.
You need to be extreamly careful with high temp oil seals. I have really been having problems with oil temps to 375F especially if their is contamination in the oil. John Crane recommende the MLS Multiple lip seal design, only lasted 1 month, bellows seals collected large amounts of debris at the internal seal ring then failed. Ensure your product is very clean or a mechanical seal will only cause problems. I have had very good luck with Slade packing. Replaced many J.C seals with this packing that can be tightened to zero leakoff in high temp oil applications. Look them up on the net. My customers are changing back to packing from mechanical seals in large numbers when offered this product.
Poppeye... be fair now. Packing doesn't always mix well with process fluids that have high concentrations of solids. The rings can trap the solids and grind away at your shaft. (especially that soft graphite packing you've described) Quite a lot depends upon the individual process and the flush possiblities that can be supported.
What application was that lip seal suggested for? I'm sure that we can come up with something better suited for your situation.
