Sako TRG stocks are very pricey. A 700 action would have be modified to fit into one, as there is no 700 style recoil lug on a Sako TRG action. It think it would involve a fair bit of machining to get it to fit. There are three parts to a TRG stock, the rear buttstock, the chassis, and the forestock. The folding stock options I have seen for sale, are the replacement for the buttstock section only, not the entire stock system. Very cost prohibitive. A McMillan A5 is a close match, but does not have the chassis system. I don't think it would really matter that much (at all) as far as accuracy goes.
R.