Look up Spumps. If you are handy with tools and have the time, try making one.
For an Spump, you will need to modify the bolt, hammer, and valve pin and will use a Trilogy pump kit. You will need some sort of sear so either you will need a new solenoid or will have to find a mech frame. Also remember that what you do to your internals will be mostly permanent. Alternatively, you could try to find a Trilogy pump gun somewhere on here for basically money equal to the amount of work out in.
Keep the spyder and repair it later but get a cheap Trilogy to play with.