I think you should build a .25-06, I know I did and have never regretted it. Of course I came to the decision based on what chamberings I already owned. I had a .270, .30-06, 8mm-06, .338-06, and .35 Whelen by the time I decided to go with a .25-06, it was that of a .375 Whelen. In the end the .25-06 won out because I figured I'd hunt more varmints, pronghorn and deer than dangerous game.
My rifle started life as a Zastava action with set triggers that I purchased off of Wildalaska here on the forums. Next I picked out a stock from Richard's Microfit from what they had instock. I wasn't happy with the stock design being a roll over Monte Carlo but it was exhibition grade Carlo Walnunt and I figured I would reshape the stock into something more eye appealing to me anyway.
So I dropped my action and stock off at High Tech Custom rifles here in Colorado Springs. Talking it over with the gunsmith I settled on a Lilja SS 26" magnum contour barrel with recessed crown, and to have all the metal work covered in KG Gunkote in semi-gloss black. While it took longer than it should have for me to get this rifle complete and one stock change because my first stock had a flaw that caused it to break in two at the recoil lug area. I'm very pleased with the finished product.
The final build was:
Zastava LA with set triggers
26" SS Lilja Barrel #5 contour
Metal work and blue printing done by HTC rifles
Stock Interarms Whitworth pattern used take off
Full lengh bedding and inletting done with the help of a friend
Decelerator recoil pad installed by Weaver Rifles
Metal finish KG Gunkote semi-gloss black
Stock finish Minwax Antique Oil done by myself
Leupold windage adjustable base and Leupold low rings
Bushnell Elite 4200 4-16X40 AO
It is a shooter as well!
So far I've claimed one coyote, pronghorn and mule deer with it. It is a little heavy to carry for a long period in the mountains here. If I had to do it all over again, I'd probably use a #3 contour. The barrel does heat up really fast, and throws the 4th and 5th shots but she'll still do under an 1" for all five shots.