Good move. Will cost more but you should get a way better rifle. Just besure you get a smithy that did not get his gunsmith degree for a community collage. Find your smithy first. Some will have a deal on a action that they have from a used rifle and most have a barrel or two they prefer over another like douglas or kreiger and can help talk thru stocks and triggers for your perpose and help with a choice.
My custom is mild build on ruger 77mkII SS action, 27" kreiger #8 profile in 7mm rem mag With a boyds JR laminate stock and a 1 1/2lb timney trigger. Good with some old hornay 139gr heavy mag for 2" at 400 yards. I can half that with some hand loads i had but why bother. Scope is an old first year simmons 3.8-14 scope atec. Planed on changeing it when it was built but again why. This has been rock solid hunter for 15 years now. Check the barrel company sites. Some will take your barreled action and fit the new barrel to it with all machining done for you. Just have to make the chaice's and they list the actions they will work with. Heres Kreiges site. http://www.kriegerbarrels.com/
Have you looked at the Winchester Model 70 Laredo with the boss?...I have a custom with a Hart Match Grade barrel,in 300 Weatherby.Great accuracy , I think better than the Sendero(I had one 7mm Mag)...didn't like it...Good glass is paramout with a good rifle..