i found some pretty good sites using google...
try different search terms.
also check at cisco. their design docs and product specs for dhcp manager and high-availability are really good. they've been adding more items recently.
i know this answer is relatively lame but i think you're browsing through some good search returns will likely be as effective as asking for good links.
i'm not discouraging it in anyway but it might allow you to post a followup to this posting with a request for something more specific like "i've decided to stay/go with suse 7 for x, x, and x because of y & z." maybe someone can then add "well suse 6.4 had a bug where an actual interface couldn't be specified on a high-availability cluster" (just made up).
for starters, i'm curious... what distro's are involved? anything homegrown by requirements? how much are you willing to spend and over what time (approx - i'm not a salesman)? why redundant dhcp (2000 clients with a bind server)? ...
i think i'm like most geeks in that i accumulate mass amounts of garbage that deal with the subjects you ask about... being more specific would encourage a response from packrats/ppl like me. heck, there could be a thread on redundant dhcp links/thoughts alone!
best,
matthew