What are some good options for an affordable .22 Bullpup "Air Venturi Avenger".

First let me say I have an Air Venturi Avenger and a Huben K1. The Avenger is a very consistent shot for shot machine even with Crosman Hollow point ammo. My K1 has been modified with a choked LW barrel and a Huma Regulator. With those mods it still has a hard time beating my Avenger when it comes to accuracy and this is with the K1 shooting 18.13gr JSB compared to the Avenger's 14.3gr CHPs. The K1 shooting from the mag has pros and cons, one con being that certain ammo doesn't fit in mag well and this shows up in accuracy.

So I do love the Avenger and never had a problem with it (at least 20k rounds through it so far). The only thing I need changed is how long the darn thing is. It's almost 50" (1.5' longer than the K1) with my DonnyFL adapter and moderator (which are both 100% necessary).

I have an M3 impact compact on preorder but I'm realizing that's just silly for what my hopes are (to shoot CHPs like my Avenger does).

So now I'm looking for a regulated mag fed lever action compact lightweight bullpup PCP with adjustable power hopefully for under $1k. After being into Airguns for 1.5 years I'm finally realizing what is important to me as well as what makes me happy.
 
you are not going to find it for under $1000, maybe not even $1500, unless you go with the Turkish made guns, Crosman/Kral offerings or Hatsan. it's not externally adjustable and not regulated, but I like the Hatsan Flashpup, I own 4, not a bad gun, but for what it is it's accurate and powerful and light, I did a Re-crown on all of mine which improved the accuracy even more, maybe that's what your Huben K1 needs, just an Easy crown job, look up on youtube "DIY how to crown a barrel" only take a couple minutes to do.