When building a custom guitar it can easily get overwhelming with the amount of choices.
You have to chose scale length, pickups, tuners, bridge, all your woods. Since it is a semi hollow body, will you have a solid block going though it and that will help with sustain or if there is no block is more hollow and may give you a fatter jazzier sound.
I would suggest that you go down to a guitar center and start playing the higher end Gibosn 335, 359 and others, PRS semi hollow bodies, Gretsch. Ask about all the woods and how they are made.
That eagle looks amazing.
Anyway take a look at other sites of people that use semi hollow bodys and see what they are using.
For example look at treys guitar. I am not sure what it is made from but I know that he tried a lot of different woods, koa, spruce etc.http://www.phish.net/faq/guitar.htmlhttp://www.languedocguitars.com/
Johnny A uses a mohogony body with maple top and mahogany neck. (that is an amazing guitar)http://www.johnnya.com/sig_flash.htm
You have a lot of homework to do. The internet is a great place for it but there is so much information you can go into overload very quickly.
One other thing to do is go to your sister's friend and if he has one that he built, play it ( and not for a minute or two) spend an hour or more with it and play everything you can. The amp can make a big difference too so either bring your amp or make sure you are playing though something very nice.