If you had caught me about 3 years ago I would have been able to help you out I was in Ithaca. If you move over to TX maybe. I know a bunch of gun owners, but not HK owners in Upstate NY.
The Best I can tell you about Light LEM is, it's a voodoo trigger. It is all dependent on how you run a trigger though. If you're a trigger slapper, then you'll not get the benefit of the trigger system. IF you've fired the standard DA/SA the HK45 is possibly the best save a Match trigger setup in the USP series. The light LEM is best in the HK45 and USP series hands down. IMO you can't lose either way. But I understand wanting to try before you buy. I think if you order the DA/SA the conversion isn't too difficult.