You've been given a quote on connecting 3 separate systems to function as one. The installing dealer is planning on using KCCIS to link all three systems to function as you have described.
Depending on how many phones will be at the outlying sites, you may be able to install a PVA card for each site and use IP phones at each site instead of using 3 separate KSU's.
The IPK has a maximum of 120 ports (including virtuals), while the IPK II has a maximum of 256 ports (not including 256 virtuals).
** I would suggest upgrading your main site to an IPK II and running IP phones at your remote sites via 2 PVA cards.
D
