To the op question, I think that 45ACP is probably a good choice. I am too looking at a 1911 and have many thoughts on it. My needs are different from yours.
1911 was designed and was refined over the years as a 45. John Browning's masterpiece.
For less expensive shooting, I have a dedicated 9mm.
Originally I wanted a Kimber. Made here in NY. They have their own foundry on site, which I thought was a plus, but I am not sure their quality matches their price. I base that on searching for Kimber problems.
One of my priorities on my 1911 is the ability for it to accept the 22lr kit. I may never buy that kit, but I want the ability.
Ruger stands strongly behind their products, and I have had positive interactions with their customer service departments. I would not hesitate to buy a Ruger product. Their 1911 is a little higher in price that the 800 you wanted to spend. I suggest that you save a few dollars more, and allow yourself to expand your options. I realize that may take time, but a few hundred more will give you a life long top quality gun.
So, my thought is raise your price a hair, and buy 45 caliber over the 9mm.
Maybe rent at a range. I am not sure you will find a high end 1911 for rent, but it may help you make a better choice.
Enjoy the process of finding your arm. It is part of the fun!!
Rich