bolts for scotty rod holder

Just bought my first rod holder but it did not come with the 4 bolts, what size do i buy from lowes or home depot?
Or should i go with rivets instead? what size?
I'm installing the holder on an emotion spitfire

Scotty doesn't come with hardware because every kayak is different and may require different hardware. If you can access the area where you are going to mount the holder then I would go with Stainless steel, if you can access the area then you are better off using rivets. I don't know the exact size, but I am sure if you do an online search you will find it.

10-24 x 3/4" Round head which can be purchased at Ace Hardware stores. Don't forget washers, nylon locknuts and silicon sealant. Used a drill bit slightly smaller than the screw and force tap the screw in the Hole; will minimize the chance of water entering the hull.

And if you decide to go the rivet route (if you don't have access to run bolts/nuts), make sure you use the expanding style rivets with the slits.  Generally find them at kayak shops (you won't find them at home depot or lowes/etc.).  Don't use well nuts as you will have to drill a larger hole for each well nut and they are not very sturdy. 

i reinforced my Scotty mounts with aluminum but you can do it with fender washers, starboard or something similar. 

http://shop.clavey.com/tri-locking-rivets-with-rubber-washer-p912.aspx

I just put in 2 Scotty Flush Mounts on my Revo this weekend.  I used 10-32 3/4 inch Stainless Screws with fender washers and lock nut bolts.  I like to get them at my local Ace Hardware. 

If you don't have access then as Craig mentioned use Rivets.  Get the ones sold at the Hook 1.

Thanks guys, great stuff. I'm learning a lot.