Lobo, it looks like you've done some excellent research.

Your choice of tx is an excellent one. As far as rx's, either rx is excellent. The Berg 5 is my choice of rx, and is the most solid one I own, including my full size JR and Airtronics rx's, I don't own a 555, but I hear they are also a very solid rx. The berg should come with a crystal, I don't know about the Hitec, but it wouldn't be hard to find one. Your issue with ch5 on the Berg is a common issue, and it can be done fairly easily. I'll see if I can find the info for you.

If you want flight time, Li-poly's are what you're after. I'm still learning about them myself, so I can't give advice on which one to use.

I'm not very fimilar with the MKII charger, but if you're going to run Li-poly's, it may be worth your while to get a good quality li-poly charger.

Hope this helped.

Jason