If budget is a little tight, I would start with the Hifiman HM-801, some recent sennheiser HD650 (does not have the veil of the earlier version), and a Cardas cable
This combo is soooo musical and enjoyable.
I just ordered the balanced card to see if it can actually improve what I am already hearing. But I wouldn't be surprised if I still prefer the sound signature of my actual set up. It is that good!
I will post my impressions once it is all burned in and I can compare...
Meanwhile, I would suggest you actually listen to the LCD3s before you purchase them if you can. I did buy a pair of LCD2 rev2 at some point, which were supposed to be miles ahead of the HD650. The truth is they are just different beasts. Sure, the LCD2s were more precise, had better instrument separation, stronger slam... but when used with the Hifiman, they also sounded sharper and a bit fatiguing to both my ears and neck!!! (the HD650 are twice as light!)
Associated to the Hifiman HM-801, I simply preferred the sound signature of the Senn HD650 by quite a margin. And so did everyone in my surrounding, so it wasn't just me.
I know the LCD3s are supposed to be better than the LCD2s but $2000 versus $300 (for used HD650) is a lot to spend hoping you like them...
That's for my two cents as far as going open cans with the Hifiman