I have a Remy Versa-max and Mossy 930.
The Remy is twice the price and worth it.
I contacted Wolverine about bringing in tactical barrels (22" I think) for the Remy but they said it maybe a long wait if ever...?
The girlfriend has a Browning Maxus and despite it's light weight, it shoots softer than the Versa-max.
Unfortunately, I haven't seen & expect any short 18.5" barrels for the Maxus.
However there is a shorter rifled barrel 24"(?) that could be obtained.
Browning isn't really into tactical but FNH is, so maybe a FNH model might work for you - perhaps contact Irunguns.
I have shot a M4 a few times - nothing wrong with it - you get what you pay for I guess.
A friend of mine who is a LEO in Colorado really enjoys the M2 the Dept. bought for him and he swears buy it - keeping in mind that his and or someones else's life may depend on it.
I would suggest that you shoot all of them first if you can, failing that you can always buy one & if it doesn't work out - sell it on the EE.
Good luck,
John