You can use MPLAB8 (MPLAB v8.92) as a programmer and debugger for both those chips with a PICKit3.
MCS won't let you do any hardware debugging, just programming. Any "debugging" under MCS is really done using software, so I wouldn't recommend it.

I'd stick with what you're doing. I still use MPLAB8 for any chips that are supported even though I use MPLABX for the others.