cjnewbs:
I thought it would be best to post in this thread instead of starting a new one as I'm not sure if i can use them all.
Hello cjnewbs,
The 25/45/85 differ only in the amount of memory. 2K/4K/8K bytes of flash, but also 128/256/512 bytes of EEPROM and SRAM.
The "V" versions can operate from 1.8 to 5.5 volts, their max clock speed is 10MHz.
The "non-V" versions can operate from 2.7 to 5.5 volts, their max clock speed is 20MHz.
The datasheet is your friend 
See the first page for a summary of features, including the memory sizes.
See section 21.3 for clock speed vs. supply voltage.
See section 25 "Ordering Information" for a breakdown of all the part numbers including package types.