Sort-of Business Email Etiquette

I'm hoping some folks have a word of advice for writing emails...

I've spent the last couple hours reading about various blogs/pages about the finer points of writing business emails in Japan, but I think I need some help.

I'm in a SOFA status in Japan, and as such, most business I'll likely conduct with Japanese people, there will be very little expectation that I know any Japanese at all. Most people in my position are expected to know little to no Japanese at all. Just to give you an idea of my skill level (or lack thereof) I know enough to get by in the country, but nowhere near enough to hold ay conversation of significant substance. However I am trying to apply what little I know. I was going to to write an email as a customer in a business relationship basically:

おはようございますXYZさん、
[Rest of email in English]

After reading about the pitfalls of not using good keigo (and how rude さん is in a business email), I was going to write something like this:

XYZ様、
「Simple greeting or thanks for earlier help」
[Body of email in English]
よろしくおねがいします
[my name, org etc]

I very nearly just said, 'screw it, nothing ventured; nothing gained" and sent it, but eventually I just got scared of screwing it up and wrote the whole thing in English, to avoid any reaction of "euch, what's this guy trying? This Japanese is a train wreck, I'm going to just pretend that part doesn't exist in my reply." or perhaps avoiding confusion as the responder would be in a position of dual formality with Japanese and American etiquette.

Am I just overthinking it? Thoughts?

Calm down.

Start all your business emails with...

XYZ様 (no comma or "touten" is needed)
(insert an empty line)
お世話になっております。

and close them with ...

よろしくお願いします。
(insert an empty line)
[my name, org etc]

They will be impressed.

おはようございますXYZさん、
is okay as long as the bulk of your email clearly shows that you are not fluent in Japanese. We often get these kinds of emails, and we think it's very thoughtful that the writer bothered to write any Japanese at all. For example, if you're an ordinary guy trying to buy something from their store for your everyday private life, this is quite a typical way to write.

Hope it helps.

How can I be calm when I got all this CAFFEINE? hehehe

But your post is actually quite helpful. It helps to get a second pair of eyes on an issue. (especially when that second pair of eyes knows what its talking about!) I'll probably have to wait no sooner than tomorrow to give it a whirl! :)

ありがとう〜