Hi, I have seen your dilema in the fórums. Just to answer you question, two Flesh Cannon = 500 Silver (Corpse Pot). Thats 500 Silver every minute. WL haves high CD yes, but grinding 2 mins if what you need to gather a packs of mobs. Both will work Fine with your Frost Pilar CD 49 secs. I believe Necro will be more expensive tan WL, but not sure.
I have seen a lot of videos of pet build, but is Sorc1 and Necro 2. The game style of pet build is for pro’s. You have to jump a lot in close combat to evade the boss attacks with the mobs so all your pets dump AI attacks all the time. Its difficult need a lot of potions and very Low Ping.
Normally people take only Sorc1 for the pet and cat bufs. In your case you are Sorc 2. Sorc3 wont give you much, but not being Wiz3 I wouldnt take Necro or WL because your damage will be 50% lower. Thats is my personal opinión.
Personally I dont like Sorc with Necro, because you will have the worst of two clases, the SP drain and the Corpse Managment with potions. If you plan to use Necro pets and use Flesh Cannon and Flesh Hoop in Bosses only It will be a Improve Sorc 2. But take in account the problems with pets Necro have:
Avoid Necromancer
Not taking Necro 2 in Rank 7 will be a waste. Future wise will be better take WL1 in Rank 7.
If you take WL, only to cast a secuence of WL attacks in 2 mins is 1000 SP. Sorcs normally have low SP around 1600, so be WL means you will drink SP potions like wáter.
I cant give you a definitive answer. Take in account the Pros and Cons of your options and decide understanding that anyone of them are far away from beign pefect.