Originally Posted by illumiquest
Pentax dropped the cloth shutter. If you buy a K2 or anything later (aside from the MX) you get an electronically controlled metal shutter.
The metering on my K2 is more than good enough for slide film. I don't really see how any other brand could be better. A light meter doesn't compensate for poor technique anyway, it's just a guide. Judging by the internet entries I've found the K2 is pretty equal in features with that FE, about the only things lacking are a motor drive (unless you find a K2 DMD and the matching winder) and the user changeable focusing screens. If those are desired then finding an LX will give you both, along with TTL flash, a 1/2000 top shutter speed, and interchangeable viewfinders.
As for "older" they've kept the K mount since 1975. So you can pick anything between a 1975 K2 and a 2001 MZ-S and use any K lens with an aperture ring (all of them apart from the FA-J and DA series, the only other exception are the cheaper bodies with the "crippled" K mount which you probably won't want anyway). You can use the earlier screw mount lenses with a simple adapter, although you don't get open aperture metering that way.
I'd look for the best condition K2 or K2 DMD (rarer but with a few useful additions over the normal K2) you can lay hands on then have it CLA'd. If you can spend a little more then doing the same with an LX will get you one of the best 35mm SLRs ever made.
As for adapters, is the lens you have an SMC Takumar or an SMC Pentax? Optically they're pretty much identical, but the SMC Takumars were the last series of M42 screw mount lenses while the SMC Pentax were the first K mount.