Overall they're very nice boats. With twin engines, nearly a 14' beam and low center of gravity, a great all around boat for coastal cruising and inland waters. I might add, it's also a very stable fishing platform if that's your thing.
The T6-354 is a long lived engine and parts are still readily available. The exhaust system for the turbo charged version is available in cast iron from Barr and several after market sources. The 6-354 NA exhaust manifolds are pricy, custom built by MESA Marine. They are not interchangeable as they have a different bolt patterns to the block and exhaust riser. I've replaced both of mine with stainless from MESA. Same with the exhaust rises.
I've seen 6-354's with more hours than that, still performing quite well. Usually these engines die from poor maintenance and neglect, before they wear out. I would definitely insist on an engine survey by a diesel mechanic who is familiar with Perkins engines.
Best of Luck
Careful . . .I Have a Generator and I'm not afraid to use it !