when you get into trimix you actually tend to need less of a wing because your backgas bottles become less negative with the added helium
regarding AJ's comment. E7-120's are the biggest tanks for 7", they carry 20lbs of gas, plus about 15 or so pounds between the backplate, bands, regulators, etc etc. 35. Gives you a 10lb buffer with a 45lb wing and that will cover a pair of stages and a deco bottle. It's cutting it super close, but that's why you would only ever dive that configuration in a drysuit and why it is unsafe to do it in a wetsuit....
With 95's, they carry about the same volume of gas, but the 45lb wings are usually a little narrower so they can't fully inflate which is a problem, and with tanks like the 104's, you have to add an extra 5lbs to their negative buoyancy, as well as another 5lbs of gas, so that puts you in the range of a 55lb wing.
With wetsuits you have instant buoyancy from the suit, and guaranteed buoyancy loss because of it. With a drysuit you have a pretty fixed min-gas inherent buoyancy, but it is very unlikely for that to ever be 100% lost. Everything except a torn leg/foot will allow it to hold some air. That said, those rigs are also so incredibly heavy that I don't think I've ever seen anyone actually put extra lead on when diving with a drysuit, so you just make sure the whole rig can be supported by the wing, and in the event that your drysuit floods, it's no big deal, just one big bubble instead of two somewhat smaller bubbles. Very manageable.