Writer's Block

So I've been struggling for months now trying to finish up my Thailand support letters. Sometimes I hate my perfectionist tendencies because the fear of doing something poorly can keep me from doing it. I think I have two versions of the letter right now, one on my Mac and one on my computer at work. But I'm realizing that if I want to make it to Thailand, I need to finish the letter and send it out very soon. I'd love to have some feedback from people who have successfully written support letters before. I think that's where part of my problem lies- this is the first time I've ever written one and I want to come off sounding genuine and not too money hungry. After all, this isn't just about me.

Here are a few things I'm struggling with as I write, let me know what you think:

• I want to pour out my heart, so my friends can see the passion I have for what I'll be doing in Thailand. But unfortunately, I'm long-winded and pouring out my heart usually results in two full pages with lots of details and adjectives.
• I'm not sure how to say that I need money. I mean, I'm sure people will figure it out because I mention that I have to raise my own budget to support myself while I'm there... but I haven't found a comfortable way to state my need and give a "call to action."
• I'm someone who loves a lot of details. It's something I struggle with sometimes when I'm writing news stories for work. I want to know everything and how each detail fits together logically, but I have to tell myself that not every reader wants to know every minute detail. Most people prefer to have the story as a whole. So my problem in writing the letter is feeling like I should tell potential supporters every detail of my call, preparation and upcoming ministry, but no one wants to read a novel. (As you can see by this bullet "point"/paragraph, I really need to work on this.)

So please give me some feedback. If you were to get one of my support letters in the mail, what would you want to know? What would you want to see? What would be off-putting? What would make you want to give?