Hey there @Chadakkina
First of all : welcome to S.A & the forums
Hope you'll gonna enjoy ANA 2, it's a great sounding synth with nice features, just need some time to get around it's features ( like any other real hardware or soft-synth indeed ). Next to referring to the manual, if you haven't been through the ANA 2 tutorials yet, it might be a good place to start. All ANA 2 video tutorials are free to watch on S.A website, just use the magnifier search icon on the top right tutorial page and type in "ANA 2". You also have a walk through series & many free ANA 2 videos on S.A YouTube channel here : ANA 2 full Playlist .
Back to your question about getting a Midi Controller
It really depends on what you'd like to control and what you're aiming at : are you looking for something more playable like a keyboard & controller for midi instruments ? Or is it to get more control on the DAW ( Reaper ) itself ?
Then like @majesticpillow already mentioned, having some pads can also be useful if you plan to trigger drum kits or even play some instruments if you're not a keyboardist player. Some controller's pad will only allow to play single notes while others might have some chords & scale features.
Basically, the type of physical controls that you'll find across Midi controllers are Push Buttons, Knobs & endless rotary encoders, Faders, Pads & of course Keys whenever there's an integrated keyboard. When it comes to push buttons, it might be interesting to have dedicated controls on the Play/Stop/Record features from your DAW. Faders can be useful to control tracks level, anything that allows you to control Mute/Solo/Pan feature inside your DAW is a nice addition.
So it really depends on what you need and how well the controller will integrate with your DAW. Push & Push 2 are really designed to work specifically with Ableton Live, unless you use a custom script to integrate it with Reaper ( take a look at this video), they are also not in the same price range.
When it comes to most soft-synth plugins and with ANA 2, next to have Mod Wheel & Pitch Bend automatic assignments on Midi Controllers that have those physical controls, you'll be able to "Midi Map" features to a physical control of your choice, so for example you could Midi Map the main Filter Cutoff to a knob.
Though I'm not familiar with Reaper and it's Midi integration possibilities, I think it's safe to say that most Midi Controllers & DAW Software Manufacturers have made huge progress when it comes to Midi Mapping and integration. Now I also know that Reaper is a very customizable DAW & that the Custom Commands feature can be very powerful and integrated to Pads & Buttons on Midi Controllers, a nice example with Novation Launchpad Mini MK3 in this video.
Brands & range of products to look at IMO :
And it might be slightly over the $200 budget range, but for a Midi Keyboard + additional features, the Nektar Panorama T4 seems to integrate very well with Reaper.
In any case, watch videos, read reviews and if you plan to purchase in a physical shop ask as much questions as you can, but before try to narrow down what is that you really need from a Midi controller & what could benefit your workflow, performance, setup.
Hope this helps