Ron, In my opinion the only add on other than the KSB2 you now need is the KAT2. I have two K2's one with the KSB2, KAT2 & KBT2 and the other with KSB2, KPA100 & KAT100. I find for my location the other options are not necessary. Have fun! 73, Bob VE3XM K2's S/N 2676 & 4031