$1000 sounds fair for a shop to R&R both front axles and supply the parts to do it right. This isn't a job that is technical but it is really messy and care must be taken to ensure all parts are cleaned and ready for reassembly. Most of us on here that have done the job will tell you the first probably takes about three times longer than the second side. If this mechanic is knowledgeable of the repair and experienced in doing it they shouldn't have any issues.
Remember you are paying someone to do a job that you are not or will not do yourself so pay them accordingly but hold them to their workmanship.
Note: If the mechanic isn't familiar with the Landcruiser platform I would suggest offering to print out the pages in the manual that show torque specs as they are important. Another thing to check, he will be removing these as part of the knuckle rebuild, are the nuts on the bottom of the knuckle as these tend to be overlooked and can shear the studs without proper torque and maintenance.
