You can, in my opinion, pound an awful pile of money into a new gun, to turn it into what you should have bought in the first place for half the money...
I'd suggest that the stock would be about the only really noticeable weight savings you can buy for reasonable money, right of the bat.
Then buy a really nice, padded, wide sling, so the weight does not dig in to your shoulder.
Set all the other "mods and upgrades" money aside, to use to buy the other rifle, put the heavy stock back onto the first one, flog the light weight stock to get some of your money back out of it.
That's just me. I'm not all that keen on spending my money on stuff that won't really drive the value of my rifle up, at least a bit (as opposed to driving the cost up, on things like gunsmith labor, and modified parts that will never pay back in the end).
The lighter scope would be another good way to shave a bit.
The real majority of the weight of the rifle is in the laminate stock, and the less than lightweight barrel profile. The one is easy to change, the other not so much. Beyond those two places, the cost per ounce saved goes up pretty rapidly to the point where you have a much customized gun that cost you more than a high end makers gun,(say, Kimber, Cooper) but will never sell for as much, used.
That's just me though. I'm feeling a little contrary right now.
Cheers
Trev