I already have 1 of the 155w panels, can I combine it with a 1 of the high voltage 280 to 300watt panels with an mppt controller?
You absolutely cannot*. Since you already own one, your two intelligent choices are buying a second one, and either keeping your current PMW charge controller, assuming it has the ability to handle twice the current, or buying an MPPT controller for the pair. You can only series two panels that are either identical in both voltage and current, or at the bare minimum, that are almost exactly the same in voltage, and are close in amperage/current.
*If you did, you would lose 100% of the extra power from the larger panel, making it not at all the way to go.