Martial Arts Sparring

I’m interested in starting a martial art that is extremely practical in real world fights and involves lots of full contact sparring.

I tried Krav Maga a while back and enjoyed it. My only complaint with Krav Maga is instructors don’t have people spar with each other in low level classes. Subsequently you don’t do any real fighting until you’ve reached higher classes, which take 6 months to a year to reach. What students mostly ended up doing in low level classes was practicing strikes and kicks by hitting thin air or simulating strikes by hitting cushioned bags that partners held. While the actual fighting style seems practical and "no nonsense", I felt the training in lower classes fails to prepare you psychologically for a real world fight where a real opponent is moving around and fighting unpredictably.

I therefore feel the only practical martial arts are ones that involve full contact sparring on a regular basis and also condition you "psychologically" to take hits, strike people ect. My question is what would be the best martial art to pickup? Again, I’m interested in raw bare bones practicality, so my interests would be more along the lines of MMA, Krav Maga, Boxing, Mui Thai Kick Boxing ect. As opposed to Karate, Tai Kwon Doe ect where you use a long drawn out belt system that takes years and practice "form" over real world strikes and hits (Note: I respect all martial arts and I’m not criticizing Karate or more traditional marital arts they’re just not what I want). I also don’t care about competition events. I’m only interested using this as a last resort for self defense in the real world.

I’d be willing to go back to Krav Maga if higher classes have more sparring. But I’m wondering if this is the best route, or if something like MMA would be better because it seems to have more sparring. I would appreciate answers from people with real experience doing the above martial arts in one form or another. Thanks in advance.