not sure how the prices compare but you can checkout www.nuvico.com for their Apex Lite series also. They have some demos online to checkout and support mac via java client also.

although we don't support speco on our mobile phone apps we have analyzed it and they do have one of the more secure mobile authentication mechanisms we have run across.

i have seen the icrealtime iphone apps being used by other companies (GUI is too similar for coincidence).

q-see is straight OEM from what i have seen. their iphone app (along with most free ones) is possibly server based.