Re: First time questions
First off, welcome to the "hide".
If you would, tell us a little more about what you're planning to do with this rifle. What distances are you planning on reaching out to?
With a 2K budget or preferrably less, you should be able to get yourself some nice glass.
Take this as advice from just an "average Joe" - I'm no optics expert, nor a trained long range shooter. You may want to start reading and researching FFP (front focal plane) scopes that have turrets (knobs) that match the reticle - either in Mils or MOA. Many around here prefer scopes that are in Mils because the math is easier to put to use when using the scope. If you are familiar with one or the other, pick your poison.
As far as the reticle goes, you can pick from quite a few depending on the brand of scope you fancy and the type of shooting you will be doing.
If you wish to do so, you could move this new scope between your .300 win. mag. and another rifle like a .308. All that would be needed would be to mount it to the "other rifle", then go out and shoot it to zero the scope to the new rifle. As long as you know the bullet drop for whatever rifle you are using the scope on, you will be able to use your reticle to either hold over for shots, or dial in the correction.
I personally like FFP scopes as the reticle grows or shrinks in relation to the zoom power you set the scope to. What this means is that no matter what power your scope is set to, the reticle can be used for ranging or corrections.
In a SFP (second focal plane) scope, the reticle always stays the same size and is only accurate for ranging/corrections at a certain power. At any other power, you'll have to figure in a correction factor if you are using it for ranging, holdovers, or dialing in corrections.
Here are a few in no particular order that you might want to research.
Vortex Razor 5-20x50.
SS 5-20x50 sold through SWFA.com only.
Vortex PST 4-16x50 or 6-24x50 available in FFP or SFP
Do yourself a favor and look up
http://www.libertyoptics.com/index1.html
Give Scott a call and talk it over with him. He knows optics and he'll treat you right.
Don't overlook getting a good base, maybe a 20 MOA and a good set of rings too if you don't have those.
Sorry I'm not more help. Hopefully others much more knowledgable than I will chime in.
Good luck.