The most common Alps "starter" is the Dell AT101. It has black Alps, which are linear, and depending on who you are talking to, might be slightly tactile or might not.
These boards are common and relatively cheap, but beware, while a good one is very nice, a bad one is not pleasant. Do not judge all Alps by a bad AT101.
Apple Extended Keyboard and AEK2 are good boards, the AEK2 is also plentiful and cheap, but will require an ADB-to-USB adapter ($25 on ebay).
From there, they get much harder to find and more expensive.