There's a few factors you need to consider before deciding.
1) what level of offroad use? light trail riding/nothing crazy you can go with a lower cost setup
2) are you installing it yourself? if not, install will likely take up $300-$500+ of the budget
3) if you want to go over 2" lift, you'll need to get aftermarket UCAs which again will be another $300-$500+
I run the Eibach pro truck kit. It's been great so far though I haven't done much offroading with it yet. I got it for $505 shipped with $250 Icon 3-leaf AAL for the rear. Installed the rear myself but ran out of time and had a shop do the front for $180. After buying some tools and stuff I spent around $1k. However, I don't plan to do any crazy offroading as I live in FL and my options are pretty limited.
Eibach is also announcing/releasing a Stage 2 kit sometime this week I think so that might be something to look out for. Not sure how pricing will go on that.
Also, for the rear you might want to get a HD leaf pack if you're gonna have a topper and additional static weight. They run around $600+ whereas an AAL can be had for a couple hundo. Also disclaimer: I'm by no means an expert here, this is just what I found in my months of research before buying my lift lol