I'm where you're at pretty much. Here is what I have put together after reading volumes of posts on this and other sites for many months. Semi-custom 7mm Rem Mag shooting HSM 168gr. Berger VLDs through a 24' Shaw barrel. Action is Savage all bedded into a thumbhole laminated stock. Topped with a Leupold 8.5X24X50 VX3 that carries an anti-cant device and a ACI. I tagged a Dell Axim PPC off ebay and purchased an extra battery for it. I purchased Loadbase from Patagonia Ballistics and put it on both my PC and the pocket PC. I bought a Kestrel 3500
to give me the environmental data. Swarovski LRF to help me get the acccurat yardage.
Now let me tell you one of the most important things I acquired that I would also recommend to you.
Applied Ballistics For Long Range Shooting by Bryan Litz. The book is a wealth of information that helps understand much of the technical aspects of the undertaking we're getting into. Don't let much of the really techy stuff turn you off. Read it and then read it again. It's certainly not the only rsource out there, but it has really helped me understand a bit of the challege I'm getting into.
Now like you, I will have to run copious amounts of ammo down the tube to ascertain just what my rifle setup, my ammo, and more importantly myself can do as regards ethical long range hunting. I look forward to the challenge and am fully prepaired to accept that 800 to 900 yards or somewhat less may be my max range all things considered. Hang in there and be sure to take advantage of all the knowledge and talent that is on this site. I know these folks have really helped build a fire under me for this pursuit.
Now off to practice, practice, and practice some more. Plus I still have to lay in a fair supply of batteries for all the machines to operate on