You will need the larger reflector to receive a reliable signal for 118.7, as pointed out it is Ku FSS and operates at lower power than DBS.
Also, it would not hurt to receive the other sats for the constellation/arc along with 118.7 as Dish can AND DOES, on occasion offer International services on OTHER than 118.7 for special events or can move internationals to other sats on the arc should 118.7 encounter problems (perhaps loss of a transponder or more) either temporarily or permanently. Dish really wants all subs to have full arc installations to provide critical back-up if necessary so everyone can continue to receive all of their services in case channels have to be shuffled around (as what occurred on the EA not too long ago).
At minimum, you would need the dual band LNBF from Dish that looks at both 119 & 118.7 along with the larger reflector. That should provide you with the minimum set-up you SHOULD have for reliable operation. However, I don't know if 9 day program guide is still at 110 (on the WA) only, so that may affect your DVR.
It isn't that much more expensive to get the 2nd LNBF (the first one is a dual band-2-in-1 LNBF) and install it providing you with a full WA. It is a bit different for the Eastern Arc.
