No FTView is "Least Cost". Get rid of that thinking right away.
FTView SE, whether distributed or standalone, is licensed by the number of display windows you anticipate needing. If your application needs 15 different displays (not monitors, but actual graphic windows) you purchase a 25 display license. If you need 195, you purchase a 250 display license.
Nobody here can answer as to what product you actually need.
As for what version, install the latest. Why bother with anything else? For the record, the latest is 8.1, which FINALLY gets rid of the 25+ year old string/numeric entry keypad, but doesn't fix anything else.
If you don't have it, download the free ProposalWorks application from Rockwell. It has current pricing on all of the products that they offer. And your distributor doesn't discount Rockwell Software hardly at all, so you can use the ProposalWorks prices as accurate.