Guitar Audio interface

[B4 Sloth]

Having had my guitar since september I have learned a number of songs...mostly in part.
Most of it is Metallica, earlier stuff.

I want to start piecing it together, sampling riffs and building it up into a track. I know some interfaces (Novation Nio for example) have ability to do a lot more.
My needs are simple, I want to add the riffs and stitch all together, ideally with a product that has drums/ basslines available for the songs.

A number of products are out there, even one for the iphone.

Dont want to go mad, 100 quid tops. More i spend on this is less i have for buggy.
Thanks