I think the Remington Model 700 SPS is the right way to go, but not just any SPS. Lean toward either the Model 700 SPS Varmint in .308, or the Model 700 SPS "Long Range" in either 7mm Remington Magnum or .300 Win Mag, these are the only factory built Remington SPS's with the heavier varmint profile barrel that you would need for long range shooting, they are best for long range accuracy.
The key to 1000 yard/meter shooting is keeping the bullet "supersonic" at the target. The higher the range elevation, the "slower" the speed of sound. The .308 is marginal for 1000 yard shooting. IF the "Long Range" were available in '06, that would give you a better margin. AS much as I like the .308, and that ammo is more readily available, 1,000 yard/meter shooting (especially at sea level) is pushing the capability of the round. If I were you, and reloading components are somewhat available to you, I would lean toward either the 7mm Rem Mag or the .300 Win Mag over the .308 ... both will get you to the 1,000 yard/meter target above supersonic speed.
Barrel life for a .30 barrel fired in competition settings is about 3000 rounds ... a little less for the magnums. For the 7mm Rem Mag, you are looking at about a 1500 round accuracy life, because the magnum rounds tend to "erode" the throats of the barrels more quickly.
Barrel replacement cost is dependent upon the 'smiths in Australia and their going tariffs. I would lean toward a Hart, Douglass, or a Kreiger barrel over a factory barrel. Price would be dependent upon cost after importation and the 'smith's rate to install and chamber the barrel.
Recoil for the 7mm Rem Mag and the .300 Win Mag will be in the 20-28 foot pound range ... about 1.5 times the amount of the .308/.30-06 and perhaps twice the amount of a 12 ga shotgun. I can not offer an answer relative to a limb saver, since I have no experience with them.
Using a .308/'06/.300 Win Mag or a 7mm Rem Mag should not be too offensive for your neighbors at the range, especially if they are wearing proper hearing protection. The muzzle blast should not be terribly more than what you get from a .303 Enfield round.
Here in the states, .308 and .30-06 is running about $1US a round. Magnum ammo is running about $1.30US, depending upon where you find it. Unless I can get a good price on .308/.30-06 Military match ammo, I tend to reload my own, which is cheaper. When you are shooting 1000 yards/meters, you need match grade ammo, which surplus isn't! You need a high ballistic coefficient (BC) and the terminal velocity that surplus ammo does not provide. I tend to reload 99.9% of my match grade ammo with Sierra HPBT MatchKings. Both the 7mm and the ,30 MatchKings are PROVEN for 1,000 yard/meter distances. You will need to get into reloading. Check out the prices of powder, bullets, and powder locally, along with the price of brass.
For 'scopes, I would lean to the Weaver T24 or a comparable Leupold design for target, and a lower powered scope, such as a 6x. Here in the states, for 1000 yard shooting, we have to shoot primarily iron sights, and then some scope matches.
With respect to accuracy potential, given ammunition that is mated to your rifle, and a proper match grade bullet, your rifle (provided it has a "heavy barrel") should be able to deliver 1 MOA groups (or better) at 1000 yards/meters, provided you have/develop the skill to deliver it.
To better understand the complexities that you must overcome for 1000 yard/meter shooting, you need to have some resources. Try to get a copy of the Sierra Reloading manual (or comparable in Australia) and a copy of the Sierra Infinity ballistics program. That program is invaluable to long distance shooting!
When you start shooting long range, you need to find out what bullet your rifle shoots best with whatever powder/primer/brass combination. This requires a lot of range time for load development. What helps to make this easier is if you have a chronograph, and while you shoot for "group size", you also so to measure the bullet velocity and search for the best/lowest standard deviation in velocity. The reloading compromise you want to get to is the best group size WITH the lowest velocity standard deviation. You might get lucky right off the bat, but this could also take you a month or two of range time ... bottom line is, you must be patient and diligent!
If you contact me via email, I can provide you the name of a fellow Aussie that can help point you in the proper direction for long range shooting!
Good luck and good shooting!
ETA: If your heart is set on a .30, go with the .300 Win Mag.
Master Class competitive rifleman
Expert Class competitive pistol shot
Reloader of over 124,000 rounds
Over 30 years of firearms and reloading experience
NRA Endowment Life Member