The 501st doesn't discriminate against facial hair, even though the only facial hair we see in any of the films was that of Admiral Ozzel. The 501st doesn't discriminate against the wearing of eye glasses, either. That may not apply to you, but I thought it necessary to point out.
I wear glasses but typically don't when I am in costume. I don't sport any facial hair because I am required at work to be clean shaven. We are a costuming club that boast screen accurate costumes that look like they could come of the big screen. It is up to you if you wish to be clean shaven or not. Having your goatee will not disqualify you from becoming a member of the 501st. As Matt (Oomar) had pointed out, there are many a officer within the 501st that have various stages of facial hair, as well as glasses.
For your boots.... you could go to a horse tack store, if you want, but those would be extremely expensive. My advice would be to look up East German officer boots. There are some for about $80, provided that they have the right size. Go here:
http://www.wephaus.com/products.php?cat=15 (look for the
German Army Parade Dress Boots, the third one down the list)
- Bill