I think you can manipulate the Jawas to drop weapon upgrades?
EDIT:
Well, good news and terrible news.
First the good news:
You can manipulate Jawas to drop what you want! Joy!
Bad news: You aren't ever going to do this. Infact, I suggest you actually stop making this run until snes9x 1.5 is ready, or whatever version of zsnes.
No it's not because of the sound (though I now have a headache after making this for you), but because the emulator will desync.
The first time I manipulated the Jawas I got three Vader Masks. Played it back, and I got a time extend and two nothings. Ok...
Manipulated again (keeping the clock) and got a lightsaber and a thermal detonator.
Played it back and got nothing.
Tried again, don't remember what I got, but it turned out as nothing on playback.
Decided to just try to manipulate one drop instead of two. And after about 15 tried I got a shield.
Good luck getting a gun at that rate.
On a side note: The speeder level isn't going to be fun. As shown you can manipulate Jawas to appear instead of random terrain items. The speed at which you approach the sandcrawler is based on how many Jawas you kill, not on how far you drive.
YOU CAN MANIPULATE IT MUCH BETTER THAN I DID. I JUST DID AS A PROOF OF CONCEPT. Also, I can see people's motion sickness setting in...
Edit2: Ahahah I just downloaded it from microstorage and watched that, and the second Jawa didn't drop the shield that time. Oh boy, good luck trying to get a detonator before each boss.