Two Serial Ports Struggles

I am having a difficult time talking to two different serial devices. The heart of the problem is this: One device is using 7-e-1 and the other is using 8-n-1. Since it seems impossible to define those parameters, I can't seem to get them both to talk correctly. Any libraries out there which would allow me to "lock-in" the 7-e-1 on one port and 8-n-1 on the other?

You could just run both as 8N1, and generate parity in your own code (if it's even needed: there's a decent chance that the device at the other end is ignoring parity).

Unless you're desperately short of flash, it's a simple matter to generate a PROGMEM table that translates the 128 possible 7-bit values to their "parity-ized" versions. Then you just and the incoming bytes with 0x7f to discard the parity.

There are instructions around for reconfiguring the hardware serial uart to generate even parity. It's a simple matter of re-writing a config register, even though there's no "high level" arduino function to support it. Search for "parity"...