We have both Alpines and LaManchas. Love them both, and both have great milk. Bad tasting milk may mean a particular goat has mastitis.
My Alpines and LaManchas are about the same size.
BEFORE you jump off into this, learn about goat health. It's absolutely essential that you buy goats that have documentation that shows they have been tested for and are free from CAE (Caprine Arthritis Encephalitis).
Also, it's all about teats and udders. The udder must be 'well attached.' Look at the dam's udder. Is it pendulous and hang loosely when viewed from the back? NOT a good thing. Teats need to be big enough to milk easily by hand. Itty bitty teats will give you hand cramps and milk in your shoe.
Stunted kids may have had their guts damaged by coccidia and/or worms. Ask about her coccidia prevention plan for kids and deworming practices.
Read about goats ..... a lot!
Here's a good place to start:
http://fiascofarm.com/