I'm with butterbean - his assessment is on the money.
Be aware that if it's cracked manifolds, you're looking at something like $3k to get a shop to fix it (with a set of long-tube headers and uprev tuning to correct the leaning that will cause). Any other fix is wasting time and money, as they will crack again, and likely sooner rather than later. When you're talking about $800-1200 in labor alone (and another $1500+ in parts) you don't want to pay the labor but once.
The electronics could be something simple, but it could be a huge warning buzzer. Has the truck ever been wrecked? Verify the title is clean (with a title history, not with some bunch like carfax, which is worthless based on the rebuilt truck I once bought which had a clean carfax report...) and have a shop confirm it's never been wrecked. It could be as simple as a fuse or relay or two, or some sort of wiring issue (but that's not simple to diagnose).
If the truck is priced right, and by right I mean something like "cheap" and you really like it, it might still be a good deal. But a decade old truck with 130k and issues can't be priced at $15000 and be worth it at all. I'd be looking at something on the order of $10k or maybe $11k with the issues it has, and that's if I could get some confirmation the cruise and radio issues are the only major issues and they're not due to some sort of deep-in-the-dash wiring hack job by someone other than the factory assembly line.