Importing Doom Instruments

So I'm messing around with Anvil Studio (if you know a better free MIDI editor that doesn't require an instrument I would love you).

I opened E1M1 to get the instruments, my guitar can sound close to the Doom one so I wanted to make some simple rock songs. For some reason when I import the Doom song it messes with Anvil's notes, only allowing me to use 3 of the longer period ones (I never learned music so I don't know what to call them sorry).

Any way of just getting Doom MIDI instruments from the net or something? I have a feeling there's probably some simpler way of making MIDIs but when I search for info I just find stuff about plugging pianos into my PC :\

eh nevermind i found them already in the MIDI editor D:

damn this MIDI business just mystifies me