[Moppie]

If your quite comfortable rebuilding heads and the rest of the top end then doing a bottom end will be no trouble at all.
At the end you will wonder what all the fuss was about.
Iv always thought the top end involved far more fuss, and Iv usualy left the head to the experts to put together.
But Iv worked on bottom ends on engines that are still mounted in a car (on a hoist, lower subframe, remove sump, pull bearings till you find a bad one).

And of course it sounds like the only way you can be certian the job gets done right is going to be to do it yourself, and to do it properly.
And that means pulling the engine apart and cleaning out all the oil ways.