I'm sure your questions already been answered - figured I would throw my experience/opinion in the mix anyway.
I too wanted to build a 1911 from a kit a year or so ago, but due to being completely impatient I ended up just buying one (the Para USA GI). I loved it, it shot better than expected for the price I paid and it gave me a chance to actually learn the firearm. I do agree with others that have replied that it is good to buy one built, learn the weapon, then build one. However, if you jump right into building one, it is also a great way to learn the weapon if you are willing to do some research and deal with the possible frustration of trial and error. The great thing about building one from a kit is you get to customize it to exactly how you want it, and you get the satisfaction of finally finishing it and seeing that finished product. With my Para 1911, I paid around 500$ for the pistol new, then over time dropped about 300$ in new parts (ie. VZ grips, stainless trigger, hammer, slide release, mag release, thumb safety, and beaver tail). Currently the model of Para 1911 that I bought retails at 700$, + the 300$ for the parts I wanted - I'm not sure if I would have saved money and been as happy building my own or not. I use all Wilson parts for the parts I've swapped, and it still fires beautifully with no failure to feeds after about 800 or so rounds.
So - after that wall of text - what are your intentions with the 1911? Are you looking for that satisfaction of building one yourself and customizing it to exactly how you want it, are you trying to save money, or maybe both? If trying to save money, look up your "dream" pistol so to speak, see what those cost, and then go onto Brownells or a similar sight and put a cart together to see what it would cost for parts and tools vs the completed pistol. If you're looking for a project and satisfaction of seeing that finished product, I say go for it, try building one and with an experienced gunsmith willing to help you as well as info on the internet and people on these forums, I think you should be able to do it and build something you end up being proud of and happy with.
"It does not take a majority to prevail... but rather an irate, tireless minority, keen on setting brushfires of freedom in the minds of men." - Samuel Adams