If you reload and you want easy peasy I'd go 20 Practical. It's a straight necked down 223 and any 223 bushing die set, with the appropriate size bushing, will work not to mention 223 brass is easily available. The 204 Ruger has a slight case capacity advantage over the 20 Prac & Tac as well as there's factory ammo available for the 204 also in fact if you go 204 Ruger you'll most likely have to shoot factory ammo at first to get the brass because finding new unprimed 204 Ruger brass isn't very easy.
Nothing against the 20 Tac but it requires much more expensive specialty dies and really doesn't offer any performance advantage. The 20 Tac has a slight shoulder angle change of 30° VS 23° of the 20 Prac aka 20-223 but like the other Todd Kindler creations the shoulder is pushed back to gain neck length but it also shortens the main body of the case which makes it lose case capacity so for a "improved" design that you fireform for it gains next to no case capacity over the 20 Prac. You'll hear of all kinds of amazing velocities over the 20 Prac or 204 Ruger but it's only because people are loading them to much higher pressures. Pressure being equal the 20 Prac & Tac are basically equal with the 204 Ruger having a slight advantage over both due to it having a little more case capacity.
If you are looking for more performance than either the 20 Prac or 204 Ruger will offer I'd suggest building a 20-22ARC instead.
Also, don't use anything slower then a 11tw barrel. A 10 or 11 twist will allow you to shoot up to and including all of the 40 grainers with ease.
I'm a 20 cal fan and have a fast twist 20-250 for specifically shooting the Berger 55's and a 11tw 20-222 for the 32's and 40's as well as a Tikka compact in 204 Ruger that shoots the 32's. I had a CZ 527 Varmint 204 Ruger I sold to a friend of mine and it shot the 32's extremely well also.
