Here is what you can do:
1) Your park office may know some qualified contractors who might have done work for other owners in the park.
2) Work with an agent to look for another mobile home in the park or somewhere else
Sometimes it is better if you buy another unit. It is up to you and your agent (if you have one)
San Jose Realtor
One of the most difficult tasks faced by most manufactured home and mobile home owners is how to obtain good quality repair services. Not all contractors are licensed to work on mobile homes, so even a simple roof repair can be difficult. It is one of the things to keep in mind when buying a mobile home, modular home or premanufactured unit.
Here is a list of the qualified mobile home contractors in the area. You might try contacting these service providers for estimates on repairs. If these provides cannot assist you, they may know someone who can.
The list can be found at http://www.sellerzone.com/local2/c/CA/San%20Jose/Mobile-Home
Grace Morioka, SRES
Area Pro Realty
These people can be hard to find, especially since one can cover multiple states. I find it best to go to a local modular home seller and ask them what or who they recommend. Be aware that these people aren't cheap, and I've seen the situation where the cost of their services was more than enough to make people just walk away from the situation. They are mostly about selling new and not fixing. The specialists you are looking for mostly do warranty work, and that's why they are harder to find.