Welcome to the forum, there are many 1100 owners/zealots here, and many in your general area.
Parts are not an issue, plenty of spares sitting in garages, looking for their new home.
We have an interference engine, broken timing belt = massive damage to exhaust valves- hence the concern over belt replacement.
Ck compression before tearing the engine down, they are usually good for hundreds of thousands of miles with little more than tbelt,
oil changes and NGK spark plugs
Seats are easily repadded and custom fitted to your backsides,
Craigslist- keyword upholstery, finds someone who worked in a big place and now works from home... for about half the price.
I have a lady in Modesto if you dont find one you like in SJ. Bikes come from all over for her work!
Dyna-bead or CounterAct beads are highly recommended in the tires, 2 to 3 oz in front tire and 3 oz in rear will keep them balanced at all times.
I bought a 12 oz bag online ~$10 and gave half to my riding buddy~
you can find good diy pics on www.goldwingdocs.com
Again welcome to being a Wing Nut, enjoy wrenching and riding