IMO, unless you really know what you're doing, keep it plastic, or just get a metal slide. Unless you spring for the best high end metal kits, you're more than likely to experience a lot of fitment issues that require all kinds of sanding, grinding, etc. That stuff is best left in the hands of pros who know what they're doing, know what needs to be done in advance without even looking at it, and can do it well each and every time. Personally, the only person that comes to mine with that kind of experience is Illusion. Just keep in mind that kind of work isn't cheap. It's not a surprise that his pistols cost so much. But in the end, you basically have the best of the best in terms of appearance and function.
The other option is to simply get a custom gun already built with a metal kit like the UNC upgraded custom guns. They start with a TM gun and do the full metal upgrade for you. Everything works the way it should out of the box. Again, those are rather expensive to get and you need to get someone that can import one for you.
Best of luck with your MEU.
__________________
|