For the stock springs call a decent name suspension shop. Most of those places have that stuff laying all over and can't wait to get rid of it. Just call around and ask, I got some stock ones for my 05' YZ250F for like $40. They had them laying around after they replaced some in a customers bike.

 

I just got a whole set for 50 bones.:YEAH

I just need to cut a lil foam out of the seat, and Im all set.

 

Yeah I cut out my seat so it has a 'hump' so I could use my butt more to hold on, you wear down quickly when you hold on with just your arms. Something I found out though, dont cut your 'hump' to far back ....maybe its me but I have more control of the bike the farther up on the seat I sit. Wish I woulda made my hump alot closer to the tank. I would say about mid seat would be ideal.