Mr. Pillow: IMHO, you'd be ahead doing what I did a couple of years ago when I built my custom 243AI. Here's the drill I used, total cost under $3000 for the complete rig, including all the custom smithing, optics, dies, brass, original donor rifle, ready to go to the rat patch.
I started out with a box stock M700 ADL in 243 Win to get the action with the proper bolt face. I sold the stock and take-off barrel on the internet, gained $100 towards the project. I then sent the action to Darrell Holland with instructions on what I wanted.
Doing it this way, you get
exactly what you want, with no compromises. Yours will differ from what I did, as I wanted a bench rifle, not a dual purpose. This rig reaches out past 800 yards on PD's, squirrels and chucks with great authority, shoots under .5 MOA all day, and is a joy to shoot with the brake. Here's some shots of mine for you to check out.
Here's a comparison of the standard .243 Win and a fireformed .243 Ackley Improved case: (3800 fps w/Nosler 70gr BT)
Here's the rifle on the bench during a squirrel shoot. I use this rifle for afternoons when the wind is up, and I need to wack rats past the 500 yard marker.
A shot of the Holland Quick-Discharge Brake (I can see holes appear in paper at 100 yards, or see Skippy launch every time.....)
This is a shot of a ground squirrel mound as seen through the 6.5-20X Loopy at 610 yards. Skippy is down in this shot, but was soon launched when he decided come out and cop some rays.
For quick reference, I tape "come-up" data on the inside of my scope caps, giving me instant reference to the needed elevation adjustments needed for each shot at extended range. You must have a good laser rangefinder, and have your pet load plotted via a chronograph. It's deadly accurate in the field, and enables hits beyond what you'd think you're capable of. This is the current system our snipers use when deployed for first shot hits at extended range. (It works quite well....)
Hope this gives you some material in order to make your decision. As I said, your rifle will differ, but get it all down on paper before parting with any hard-earned bucks. Good luck with the project regardless of what route you take.