I use the cross member where the tranny and engine skid meet. Best point to lift if you are putting jack stands under it. Put the jack stands where the stock jack goes.
Do you put the floor jack in the center of the crossmember? Is a 2 ton floor jack enough?
When I lift I put the floor jack under the (4) bolts at the end of the transmission cross member. This will lift the whole side. Then place the jack stand at the stock jacking point, or wood timbers under the tire. Unless I want the wheel free, I normally use ramps for the front.
I've lifted under the lower control arm also. I can't see how that is a weight concern, but it may be more likely to slide out.
In the rear, I lift under the pumpkin or under the front of the lower control arm where it attaches to the body. I see the guys at a tire shop near me lift there all the time. He told me their floor jacks last them about a month
They are outside on rough concrete and gravel.