I'm having a little trouble understanding your question, but I'll do my best to answer.

To hit the correct frame for a Mudkip (http://forums.pokemonspeedruns.com/viewtopic.php?t=499 found using this tool) you can do it one of two ways.

1. Find the timing after soft reset which hitting "Yes"/A to start the Zigzagoon fight creates a Mudkip with the correct stats as the predictor says
2. Find EonTimer settings which correspond to this Mudkip (http://www.smogon.com/forums/threads/eontimer-zomgtimer.81513/)

Not sure how much help I've been. If you need more help try the PSR Discord here: https://discord.gg/0UUw8zDe2hWlwRsm

Try EonTimer

I know you said nevermind but:

1. You need a 3DS capture card to stream good quality from a 3DS
2. 3DSs do NOT have a GBA port, the only playable pre-Gen4 games on 3DS are R/B/Y through the VC

The only option directly from GBA is to use a Webcam to record you screen. If you still want to do console speedruns then you can use the GBA Player attachment for the Nintendo Gamecube and use a capture card to obtain footage, or use a Nintendo DS (Phat) with a built in Capture Card and use footage from that. Other than that the third option is emulation, for Pokémon Emerald you can use VBA or VBA-rr