Seconding the recommendation of Festival if you could get it working (I wouldn't think it should take that much monkeying to get it going on solaris10, but as you're having problems diagnosing your linking problems you just may not be the person to do that :).

As for your linking problem, -Wl,foo tells gcc to pass the foo after the comma to the the linker; "h,libespeak.so.1" isn't a valid linker option so it's griping. Whatever made your Makefile is either confuzzled about the compiler toolchain it's using or just broken. I'd imagine it should be more like -Wl,libespeak.so.1 instead but that's just a WAG. Your best bet is to find your local sysadmin or C programmer and ply them with pizza and/or skittles and/or brewed beverages; alternately see if there's a support mailing list for the package in question and google through its archives before sending the list a copy of the problem (with relevant details like what platform this is occurring on) asking for help there.