Just let the guy who offered to make you one for $50 do it. That's very reasonable and looking at his/her work they aren't a hack and I think you would get more than you moneys worth. You'll get something professional looking. Right now you are basically asking for spec work which designers don't like which is why you probably won't get a lot of useful help. A logo is worth investing in.
If you are still set on making it your self my advice would be to go with a sans serif type face. That will get you more along the lines of clean with clean lines that you wanted.
Serif fonts is what I've heard is used most. But what about colors?
Who cares what is used most. Use what gives you the look you want to portray and what you like. You seem to be liking sans serif so go with it. You don't want to use what is used most anyways, stand out.
Just use a light gray when you have it against black and a darker gray when it will be used against white.
Something clean and simple like this is really all you need in my opinion.