Okay so here are my thoughts:
Your portfolio sounds good, but the style of those tracks were different from what I picture in this game. This isn't a problem if you can produce that style of music, I just need to know with certainty that whoever I pick can get pretty close, which was why I posted that link. If you listen to that link and feel pretty confident that you can pull that off, I think the best thing to do would be to go ahead and get started with things like sound effects, but if you're not going to produce a proof-of-concept, be forewarned that months down the line, when you do produce music, I can't accept a soundtrack that doesn't come close to that standard. That's why l think it would be ideal to have a proof of concept that I could listen to (even something short) that's indicative of that sound. If you don't do that, there won't be any hard feelings, but I'd be forced to try to find someone else (just for the soundtrack, not necessarily the sound effects). Still interested?