Bicycle Mechanics - Need to replace Cable in SF BAY Area

What would you guys recommend for my situation.

I am a newbie, as my title suggest and never really worked on a bike. I am mechanically intuitive though.

My front derailluer wire is starting to fray and forcing me to replace it. I was wondering if i should try to do it myself or have a LBS do it.
Can i Pick up any cable?

I will be going on a long bike ride late this month so i need it to be reliable.
I believe i have an shimano LX front shifters and derailluer.

If i should go the LBS route where/who would be my best option in the Sunnyvale or surrounding area. Anyone willing to help me out?

It might just need readjustment. Try looking at Barnett's Manual Ch 33 (?) on front derailleurs and see what you can find out. Usually it's just an adjustment problem. A couple of hours spent adjusting the thing should usually be enough (maybe even less if you're lucky).

If you choose LBS, I like Palo Alto Bicycles at University Ave. or Bicycle Outfitters on Foothill and Fremont in Los Altos.

My cable is fraying. I think this a definite issue. It shifts okay for the most part.

Is it fraying at the front derailleur, or along the downtube? If it is at the FD you can retwist it and put on a spot of cement or tape it. If it is along the downtube then you can buy just a cable and do it yourself with some guideance from the Barnett manual in the Mechanics section here at the forums (as mentioned above.) "Some mechanical aptitude" is the only required skill needed.

Initially, from your title, I thought you were gonna talk about cable cars.....