It's not just the high-end Galaxy S4 that deserves to have it's kernel source plastered all over the internet. Budget handsets might as well get the same treatment. To that end, Samsung has posted the code for its Galaxy Ace 3 Duos and Galaxy Amp.
The Ace 3 Duos is an entry-level handset that comes in below the Galaxy S4 Mini. It does have dual-SIMs, though The Galaxy Amp is almost the same device, but it's on AT&T's Aio Wireless prepaid service. If either of those phones seem interesting, you can poke around with the Jelly Bean code at the links below.