Rear entry wrench is fine for installing on barrels on new receivers.
You mentioned taking it beyond "hobby"- rear entry wrenches may not be suitable for pulling factory barrels (or milsurps) that have been torqued on by a chimpanzee, you risk twisting the action. You'll want an around-the-receiver style for them, so that may be a future purchase. Good idea to have both.
The Brownell's wrench was the first one I bought 10 years ago- and I've never looked back. I challenge anyone to break that bad boy- I've had a 3' cheater bar on it and lifted my 220 lbs off the floor. The wrench with the universal, and Rem 700 heads will do most anything you run into.
The only commercially available action wrench system that surrounds and supports the receiver ring and recoil lug to distribute potentially damaging torque forces equally. The solid steel base has a unique, machined relief to clear the recoil lug...
www.brownells.com