Bodies: K2 vs. KX vs. LX

[n5jrn]

I'm likely going to be doing some extreme macro photography this summer 
(in the 1X to 4X range), so I've been seriously considering getting a 
body that offers MLU.  I detest autofocus; worse, the modern Pentax AF 
bodies all appear to offer no way to get a focusing screen with a 
split-image center and a microprism collar.  It's bad enough to pay for 
a (mis)feature I don't want, it's even worse to have my choices 
crippled because of the hidden premise that I'll always use the 
(mis)feature.

Hence my interest in a classic body that offers MLU.  LX is definitely 
the best, and if money were no object for me I'd just shell out five or 
six C-notes and be done with it.  Alas, I'm poor.

Bojidar Dimitrov's Pentax K-Mount Page lists the KX and K2 as also 
offering MLU.  What's worrying is that they're somewhat old bodies (all 
25+ years old by now).  The K2 also is an electronic camera, which 
makes me wonder how likely it is that the circuit board will suddenly 
up and quit (and if it does, how likely it is to be unrepairable).  I 
also just plain have a preference for a mechanical-shutter camera, 
though I'll compromise on that if it means getting a good body with MLU 
for significantly less.  I notice Adorama's used department has a 
several K2 bodies listed for under $150.  A cursory search hasn't 
turned up any KX bodies for sale, though I expect I may see them at the 
camera swap meet in Hillsboro, OR this weekend.

So, should I even consider a K2 or KX?  Is there anything in particular 
to watch out for with these bodies?  Or should I just forget about it 
and spring for an LX?

--
David Barts
Portland, OR