Well, I just moved to Oakland a few months ago, so I guess I might have some pertinent advice. My girlfriend got a job here first, which paid for our relocation. I moved up for good about two months after she did. It took me about 3 months to land a job. The market is finicky, but there are a lot of jobs up here. Plenty of temping/staffing agencies to help you out, as well. All of my interviews came from applying through craigslist, though. You can scour it and apply before you move, but if the position you're looking at isn't one they normally relocate for, then you probably won't hear anything until you've actually moved and have a local address to put on your resume/CV.
We were contemplating living in the city, it's really what I wanted the most. But, her job was located in the east bay, so we got a place over here in the Rockridge neighborhood of Oakland. My job is actually in the city, north of the financial district a bit, so I BART to work. Even though we live in the east bay, we're in the city pretty much every weekend. Sometimes, it's nice to just head over on the ferry or the Bart with a bike and cruise around for the day, then get out of dodge back over here at the end of it, where it's a little quieter. But there are also events that I miss because it's a bit of a hassle to get over to the city for just an hour or two at night. As far as rent costs, I don't even know if you can get studios for $1000 in the city anymore. At least not in decent neighborhoods. You could get a one bedroom apartment in Berkeley/Oakland for about $1050 or so, but the neighborhood might be so-so. We pay a few hundred more than that, but we're pretty much in the nicest neighborhood in Oakland. If you want hip and a little grit, you could look around Temescal. Berkeley is rent controlled, and you're always fighting for places with tons of students.
I don't know much about the welding field, but I'd be inclined to think that there would be more welding jobs in the east bay than there would be in the city/peninsula. But if you lived in the city and commuted eastward, you'd be going against the normal traffic and it might not be as bad. Hope this info helps some.