"Something that looks sleek and awesome" is not necesarily going to be "good". The boards we'll recommend here will be recommended for their quality, value, durability, standard layouts (for keycap set compatibility) and typing feel.
That said, the WASD Code is a very good board with MX Greens (and it has backlighting). The KUL ES-87 as mentioned before by
demik is about the best quality board you can get with Blues (there's also the Filco Majestouch 2 TKL, Ducky Shine3 TKL, etc.).
In terms of keycaps, both the WASD and KUL boards come with fairly standard ABS keycaps. If you want really good ones, do some research (
http://deskthority.net/wiki/Keycap_construction) into what type of keycaps you really want and then browse the Classifieds, Group Buys and Interest Check threads, but this can be done any time after you've bought the board. Keycap profile, material and print type are personal taste, but we can give some information about each of these if you like.
Be aware that most of the top quality, highly regarded keycap sets are not backlit, meaning the legends will not let more light through than the rest of the keycap.
Heavier keycaps will tend to dampen higher frequency sounds more than light keycaps, so that is a factor, especially on "clicky" switches like Blues and Greens. Also different materials have different dampening properties, so POM dampens more than PBT and ABS, but the weight of the caps is a bigger factor. POM and PBT are more dense than ABS, so a PBT keycap of the same thickness as an ABS keycap will be heavier.
Then there are the looks of the keycaps, of course. There are many nice-looking sets that have been made, usually to some kind of theme:
http://keypuller.com/
