Heya - sorry for the delayed reply; had a workstation that required a severe thrashing
For the price, and considering you want your material to sound its best, SAM is hard to beat because of the built-in processing. DO adjust it, or have an 'audio geek' friend do it for you - out of the box it can be setup rather overly aggressive. I have found MP3 to be the format of choice overall because of the fact virtually ANY media player will play it, but AAC is sweet sounding at lower bit rates, so if that is a concern, well you have to make that call. SAM has a built-in MP3 encoder that works well, and it's included in the price. Not sure about AAC, as I use a broadcast-station oriented playback system with separate processing, and encoders for MP3 and Windows Media. I haven't touched SAM in a few years, so if you decide to pursue AAC you'll need to do a bit of research on that issue. I do remember when I last dealt with that, it included several different encoders, and could output multiple streams at once if desired.
Personally, for the material you are streaming - again because you want to 'advertise' your work with the best audio quality - I'd suggest 96k / 44,100 (MP3) as the lowest quality for stereo audio, but it is very good if processed correctly. 128k / 44,100 will REALLY sound good when processed nicely, but 48k / 44,100 sounds a bit "swishy" to me. You DO NOT want to go down to 22,050 sampling.
As far as the embedded player, the easiest to embed is Windows Media Player because it's built into the vast majority of desktop / laptop computers in use, BUT....
I'd skip the embedded player, as a proper MP3 link will generally pull up the player associated with that format on the respective device playing it, be it a Windows computer, Apple computer, iPhone or iPad, Android, etc. You might want to do 3 links - one an ASX file that says "Click Here to Listen On Windows", a PLS file that says "Click Here to Listen On Winamp", and a basic http link that says "Click Here for All Other Players" just to cover all the bases.
As far as streaming server providers, you can PM me personally through the site and I'll give you some suggestions. It would be inappropriate to openly advertise them here.
Whew - didn't realize I was writing a novel - LOL. Hope that helps!