121 is the strongest sat IMO. STO is probably the strongest.
There is a tp on 99 that is probably the strongest for that sat, but since it is a feed, I can't say in public.
I think that they is a null TP up there in the 3700~ V range that is really strong.
107.3 has weaken some, but I can still get the Quebec mux and ASN around 53Q (was about 66 a few months ago).
As far as what to peak first, what type of LNB are you using? And what dish are you placing it on? If you are motorizing, then it may be best to peak on a standard KU and make sure that you are good aross the arc. Then.....place your Cband LNB on. The focal point for Cband is much larger so you should be good after that. Try peaking a hot TP first and make sure that your skew is good. Try a tp on the other side (V or H) and peak from there. Compare it to a weaker TP to make sure you've got a good FP.
Ex. G23 (121) STO and TVW are really hot (80+) while the A&E mux is a little weak (33-46). You may want give up a little SQ on STO/TVW if it increases the A&E mux.
The HITN mux is also pretty strong and give you a veritical mux to peak.
BTW....if you are using a BSC621, you may have some probs with the KU side, so be forewarned. Its going to take some tweaking to get both
You essentially need to find a good balance