I understand you want to do this on a budget so I'm going to tell you my thoughts based on what you have.
If using 12v only, with a single panel yer already in trouble-trying to do what you are..
I also understand where the guys above me are going with high-end systems.
With that said, I know you don't have enough power to run your pump without charging a battery, so let's back up.
To get the inverter to work properly, you need 2 panels in parallel to get the amps up. You probably need a minimum of 2 100w panels to make this work.
Not knowing what type controller you have, this can be an issue in efficiency-this is not the place to cut corners.
You really need an MPPT controller, #1. Poly panels would be best but mono will work, #2. You need an inverter that can handle the input safely and this is where you need to do some research on making sure it can optimize your input (That is maximized by your MPPT controller) to properly cycle the battery and I believe you need (at the least) 2 batteries of decent quality. Series or parallel will depend on panel type and output (usually 24v is more efficient) so series wiring is in order.
Whether you can run this at night or in the day is dependent on how far you want to go money-wise. If running day time only, then forget the battery, The controller will only provide power to the inverter when it reaches a minimum value required and the pump will kick on.
For night-time operation, things get more complex and more expensive and there really isn't any way to get around that part.
Bottom line is what are you trying to do with this kit?
The guys above have touched on the important bullets for an optimum system.
