On the cast vs. forged thing.
Forged is better, right? Well, sort of. If both guns are machined identically, the forged gun will hold up longer, will be less likely to crack anywhere, and will resist deformation slightly better.
Now though, there are lots of hybrid options. A number of manufacturers have gone to forged slides on cast receivers. Why? Well, because cast 1911 frames and slides are FAR cheaper and the lower really only serves as a holder for the magazine and fire control parts and provides a rail to keep the slide more or less aligned with your grip stance. Accuracy in a 1911 is a function of fit between barrel and bushing, barrel and slide recoil lugs, barrel and breech face, and to a much less extent, barrel feet to bolt stop pin. This last one is not something you should concern yourself about unless buying a $2000+ 1911 with a custom fitted barrel. Production guns, typically, are not well fit at the barrel feet and tend to ride the link. Not a problem for all but the most competitive shooters and very-high round count guys.
Another option is machiend from bar stock. Better than cast, but not quite as strong as forged. Kahr Arms 1911's, for example, have a machined from bar stock slide assembly on a cast frame.
In the end though, most shooters would be just fine with a fully cast 1911 like the SAM or RIA. If you want to spend more than these cost, make sure it's for features you actually need and will actually use or benefit from. If not, you are just paying to keep up with the Jonses.
