Well, you said you wanted a GI type, by which I assume you don't want the beaver tail grip safety, round hammer, etc. That will exclude the Ruger SR1911, which is an excellent gun, BTW, should you decide you do want the feature I mentioned. In fact, I'd suggest you rent a GI style 1911 before buying one, if you've never fired one before...many people (I am one) get "hammer bite" from the spur hammer, and end up putting a beaver tail grip safety and round hammer on the gun to alleviate the problem (I have fat hands and use a high grip, so it's almost a given for me.) If you're going to end up with these added features, it may be cheaper to buy them going in. You should also consider whether you want better sights (not terribly expensive to add, but depending on the model/brand, the labor to do so may be costly.) Also, if you want a lowered and flared ejection port, you should buy one with that feature going in, or you are going to pay some fairly serious coin to get that done later.
My personal preference in a 1911 is one without a firing pin safety. It makes detail stripping easier (not that one with a FPS is a great deal harder) and in certain brands some say they can feel a difference in the trigger pull with the FPS in, and then after it is removed. I don't know about that, but I just prefer not to have the FPS, as it is just something else that might go wrong...which, on a range only gun, isn't as critical.
The guns I would recommend are generally thought to be good guns for the money, and also have these things in common: a lifetime warranty and excellent customer service. I'll indicate what I think are the prices, but they vary by regions of the US (when it comes down to actually buying them in a local shop) or availability off the internet. Personally, I would not recommend Remington, Kimber, SIG, Colt, or Taurus for your purposes. S&W makes a very nice 1911 in the "e" series, but it is above your price range, and it isn't a GI configuration. I have owned every one of these guns that I am recommending and not recommending, so it is from my own personal experience.
My recommendations are:
1) Rock Island Armory. These can be found at around $425 or so, for the plain GI model, or the tactical models are around $500 (the tactical models have the added features I mentioned.) These come in parkerized finish, although some of the other calibers (like .38 Super) can be found in nickle.
2) American Classic/Metro Arms. These are another gun made in the Philippines (as is RIA/Citadel) and are also usually very good guns. They can be found at less than $500 (I paid $450 for an American Classic II, which is a commander model, that had all the bells and whistles on it.) They come in blue and a chrome/nickle finish. I don't think they come in parkerized. A common problem in these guns has been the over-sized slide stop, but that can easily be changed.
3) STI Spartan line. These are made in Philippines for STI, and then shipped to STI in Georgetown for inspection. They are good, solid guns, and you might find one for around $500 or so, in the GI configuration. The rest of the STI line, made here in Texas, gets very pricey, but they all have the same warranty.
4) Ruger SR1911. This is still a hot item, and may be hard to find. It will sell for $650 or more, if you can find one to buy. It only comes in stainless, and there isn't a GI model. There is a commander length model out now too. It is a really good gun, and Ruger is excellent when it comes to service.
5) Springfield 1911. SA makes a full line of 1911s, and the NM serial number series are assembled here, and do not have a "Made in Brazil" mark on them (if that matters to you.) The GI line has been discontinued, but may still be available in local shops or on the internet. SA 1911s range from fairly inexpensive to fairly expensive (for a production gun) but they are good guns and SA has an excellent warranty and CS program. You can still get models that have the spur hammer and standard grip safety...but again, I would shoot one in that configuration before buying one, to be sure you like it. You can (if you know how) change the hammer and grip safety later, but that may end up costing more than if you had bought it that way in the first place...especially if you have to pay someone to do it (which is highly recommended, if you don't know how.)
6) Another gun I will recommend is the Magnum Research DE1911 (it comes in full size and commander.) Now, this gun doesn't come with a lifetime warranty, but if you buy it from Gun Genie, they provide their own lifetime warranty. (It costs more through them, but it's worth it, IMO.) This is a very fine gun, made in Israel, and gets very good reviews. It will cost about $800, and it doesn't come in GI style. It also has black sights (i.e, no white dots) but you can add white dots with a touch of model enamel paint.
Good luck!
Edited to add: whatever 1911 you buy, spend some money on some good magazines...my personal favorites are Wilson Combat ETMs. The mags that come with the guns are often problematic, and this is one pistol where you do have some options to try different brands of magazines. The Wilsons are expensive, but they will take care of any problems.
