Fortunately for shooters, Lilja has addressed the issue of "drop-in" fit and now includes the shims with their 455 barrels
"This newest run of CZ 455’s 22 LR have the new shim kit design, and new ‘Lilja 2’ chamber. Please see instructions below for installation." http://riflebarrels.com/shop/drop-in-barrels/cz-455-precision-barrel/
surfclod, obviously you can't expect any build off a factory action to match a true custom BR, but you can get some impressive results that are just a fraction behind the BR rifles. It can be done with a 455, but as noted above there is a little more to it than just dropping in a barrel. The barrel is the heart of accuracy, though, and will get you like 90% there with proper fitment. Expect to polish and deburr the striker and bolt body, re-shape the striker tip, add at least a yo-dave kit, pillar/bed, and test a bunch of ammo. If you can do the work yourself and sell the factory stock/barrel, you can come in a couple hundred $$ cheaper than say a brand new Anschütz 64 Tactical Trainer while being more accurate than the
average Annie if you've done all the work correctly. Although it can happen, I wouldn't place any bets on any brands factory built rifle matching what a custom (as described above) can do. For what you want, start with a match-grade custom barrel and build off that, it is your best bet. Heck, do it on a 64 action

It'll cost more but you get a better trigger out-of-the-box, a more refined action, and a factory stock well suited to your uses depending on what you select (MPR, for example). A 455 custom with the Boyd's Pro-Varmint and adjustable comb option is also a great platform.