MPL, AMPL, or OPL?

I would be thankful for any help. After struggling with java,
Concert, and lp-files (see below for details), I'm about to give up
and recommend that my company purchase Maximal's MPL, AMPL, or ILG's
PL. Does anyone have benchmarking data (memory and speed) for these
algebraic modeling languages? I've heard that PL is slower and more
memory hungry than MPL and AMPL, but I couldn't find any supporting
evidence after searching the web. I used AMPL when I was a student,
and I suspect that learning and using PL and MPL is just as easy as
learning and using AMPL.

Don't read the rest of this unless you are wondering
about the details

I am struggling with getting large instances of a mixed integer
programming model sent to a CPLEX solver (using java and CPLEX Concert
on a Windows XP machine with 2GB of memory), but I keep getting "out
of memory" errors. I'm simply reading in an lp-file using java and
CPLEX Concert. I don't run out of memory reading the file, but I run
out of memory during CPLEX's presolve phase. We have some old C++
code that is linked to an older version of CPLEX using Concert. This
doesn't run out of memory until much later, but this isn't an issue.
I can simply start the solver back up with the best solution found so
far and repeat until I solve the problem (although I have to admit
there must be a better way to do this). Since I don't have a c++
compiler and I am not a very good c++ programmer, I can not update
this old CPLEX code to link with the latest version of CPLEX. It's
hard for me to understand why the java version of Concert runs out of
memory so quickly compared to the C++ version (even when I use the -
Xms1000M and -Xmx1000M options when running the java program).