If you do miss the DOF with the K1000 then you simply have to set the aperture where you want it, unlock the lens and turn it enough without releasing it and it will stop down. Of course the KM is the step up from the K1000 and has DOF and self timer. You can also attach a mechanical self timer on the K1000 if you need that function. With the K1000, you actually get an SLR with about the same features of the Leica MP but for a lot less money . . .
The KX is of course a solid workhorse that is fully manual with all the features including mirror lockup while the MX is the smallest manual SLR with the largest and brightest viewfinder with user interchangeable screens. It can use the same screens as the LX with minor metering compensation if you're shooting slides.
But, if you need interchangeable viewfinders & screens, compact but robust build, reliable operation, a wide range of manual shutter speeds when batteries are dead, widest unassisted single metering range as well as the only camera that can aperture priority autoexpose a scene for as long as it takes (I've tested >4 hours) while monitoring the scene for lighting change and adjusting for it accordingly then there is only one camera ever (past or present by any manufacturer) and that is the LX.