Any of the RA-Tech bolt carriers will require some sort of modification (filing/grinding) in specific areas, depending on the tolerances on your rifle.
RA-Tech does not have a good reputation of working, out of the box parts. If you're new to gas guns and want to play more than tinker, I would suggest in my opinion to stick to the stock bolt carrier, or a new stock bolt carrier rather than a RA-Tech one.
If you like to tinker and are open to the idea of grinding and modification, then get the RA-Tech bolt carrier.
There is no aftermarket bolt carrier for the WE m4 that is indestructible; the steel will wear out no matter what unless you get some sort of custom cnc machined bolt carrier with high-quality, heat treated carbon steel.