Hello Mike George,
For all that you do, your HDL is surprizingly low. I can understand your and your doctor's concern.
If your doctor thinks that treatment with niacin and statins are a good option for your health, I would take them. The concerns about statins hurting the liver are fairly overblown. Yes, you should get liver function tests(LFTs) 2 months after treatment starts, yearly afterwards, and 2 months after any dosage increases, the relatively few people that get increased LFTs return to completely normal after stopping taking the medication. These drugs RARELY ( I mean less than 1/20,000 patients) get a condition called rhabdomyolysis which can hurt your kidneys. Niacin definately raises HDL, but is not terribly well tolerated in patients because of a sensation of flushing (harmless, but irritating) that a lot of people seem to get.
Be sure to discuss with your doctor if your take your medications at your next visit!
To your health,
Neil MD