I once had a M70 458 Win Mag (post-64 action, Super Grade). The rifle sported a 22" barrel. Wish I would've kept it. The ramp needed some work to feed the 510-grain factory load, but other than this it was a sweet rifle (and I wasn't bothered by the lack of a Mauser-style extractor, but today of course I would choose such (pre-64 style), first and foremost). So, this fond memory has caused the M70 in 416 Rem Mag to become somewhat desirable.
The Ruger RSM...what more must one say? In 416 Rigby, for the money, it is a very good option. And I agree, the rifle seems to have been designed around the big Rigby, and then adapted to the others (the 375 H&H, 404 Jeffrey (too bad they botched the chamber), 458 Lott...am I forgetting any?).
The Ruger Guide Gun is a very straightforward offering...20" barrel, laminated stock, 3 rounds in the box, stainless steel, two cross bolts (helps address splitting behind the magazine box, common on the RSM and original Hawkeye 375). It also happens to be the least costly (to buy, and shoot). As for the new Ruger African (23" barrel with brake/weight/cap), this in 416 Ruger is another option, although not as bullet-proof as the Guide Gun.
The CZ, 416 Rigby (the rifle which started this thread), if done up right (rifle + post-factory work = approximately $2,300) is another contender, but also the most costly.
I cannot afford beauty (true beauty, such as a Rigby 416, made by Rigby), so I am going with function, first and foremost. In this regard, the Guide Gun kinda makes the most sense (stainless, laminated stock, short and sweet, plenty powerful, etc.). Also, given that I will spend more time in Alaska than Africa (it all comes down to cost...would hunt Africa above all else, but as we all know it does come at a dear price), the Guide Gun makes sense (especially in 375 Ruger, but I am definitely going with a 416 as it's one caliber I have not yet had the opportunity to use).