I'm a big fan of the revolver & carbine combo in the same chambering concept. IMO, it's just as practical and versatile now as it was when Colt started chambering the SAA in .44 WCF to compliment the Winchester 1873.
For my uses and ammo budget the .357 makes the most sense. I currently own three carbines so chambered: Two pre-Taurus Rossi M92s and an IMI Timberwolf pump.
I've always liked the look of the Colt "Lightning" rifles of the 1880's, too. But some nagging questions have kept me from getting one of the modern replicas so far.
The originals are said to have proven themselves as being rather delicate mechanically in day-to-day use. The only one of the several models and chamberings which lasted much into the 20th century was the .22 RF. How much of this reputation might've been due to factors associated with BP ammo and how much to design/materials is anyone's guess, but the consensus seems to be that they broke and malfunctioned a good deal more than their LA contemporaries.
I've heard that all of the current repro models have incorporated changes from the original mechanical design to some degree or another. I can see where that could well be enough for SAAMI standard pressure .45 Colt loads (functioning reliably with that tiny 'rim' on the case might be another matter) I have some doubts when it comes to how it'd hold up with a diet rich in full-strength .357's.
Modern metallurgy will make a good deal of difference in some areas I'm sure. Enough to withstand average pressures nearly double those of any cartridge the design was concieved and built for over an appreciable amount of time? I suppose we'll see in time.
I'm guessing, but given the market niche that the repros target I'd bet that the manuals for all of the brands contain some recommendations and/or cautions concerning ammo besides the standard "high quality factory only, no reloads" spiel. If those include the word "Cowboy" anywhere then I'd personally stick to loads in the .38 Spl. +P range for the bulk of my shooting, no matter who made the repro.
At about half of what Beretta et al are charging for theirs I can really see where the Taurus would be so tempting. I'd sure appreciate hearing how it works out should you decide to buy one.