I'm sort of eyeballin' the Colt Series 70 .45ACP QUOTE]
This.
If you can find a stainless one new in box. Grab it.
It won't rust.
You will have not only a nice gun. But an investment.
How many will be made in future?
As you may know Colt had to run them through the custom shop to beat the lawyers.
The only caveat is if you plan to actually carry it, the weight might be problematic.
In that case a light weight commander of some type would be my choice.
In an ACP type gun, slop in the slide is for reliability in the mud.
Tightness in the slide is for accuracy.
It's a trade off.
Finger type barrel collets are the same way.
Tight but I hear they can break.
Don't like them.