For a little simpler architecture MetaIP from MetaInfo is worth a look. We handle DNS, DHCP, DDNS, and run on NT.
http://www.metainfo.com/products/metaip/index.htm
Pay close attention to the price.
Yikes! Add to that the cost of adding another machine, NT server, and administering it, and ... I think I'll go back to my plan to write my own web based one. -- Phil Howard | ads2suck@no90ads7.net no5way22@noplace4.org no1way37@spam8mer.edu phil | stop5ads@no4where.net w3x1y1z6@dumb0ads.edu no1spam8@dumb3ads.edu at | no60ads8@spam1mer.edu die3spam@dumb9ads.net end1it31@spammer8.org milepost | end2ads0@no51ads5.net suck7it2@anywhere.edu end4ads9@dumbads0.edu dot | no38ads1@noplace0.edu stop8it3@no6place.edu no31ads9@lame9ads.com com | end4it10@no4place.org eat29me7@no6where.net a4b8c1d0@s6p5a6m1.edu