Why are you wanting to do an A5 clone? I'd assume based on your question of what is recommended that you haven't shot a rifle like that very much. So if you've already decided you want a McMillan stock and a Schneider barrel, then have it screwed on a trued Remington 700 action, add the scope you want / can afford and shoot it.
The M40A5 adds a few things over a M40A3 that won't be of much value to a recreational shooter just starting out like the Night Vision Mount and the Surefire Muzzle Break, skip these and buy ammo to learn to shoot, they can be added later if you decide they are "needed." Do you need the action "clip slotted?" To make a clone, yes but not to make an accurate rifle. Save some money here too and get a standard rail for the action.
If you haven't bought anything yet, I'm a firm believer in the "buy once, cry once" idea, but you need to find out what you need first. So before you start buying anything, spend some time at the range and see what others have, ask their opinions and ask to get behind their rifles to see how things feel to you.