Hi Cam
it's not clear what you describe here. I'm sure you have no need for the A1.
Your amp is mono, so you will need to get famiiar with the ROUTING concept of the H8000. Since the H8000 is not really created with the mono gtr rig in mind, you'll have to connect the FX Send of your amp to the Eventide analog input 1, route this analog input1 to DSP A IN1 and IN2 (so a mono signal is being splitted to both inputs of stereo presets). Then route DSP A outputs into DSP B inputs (the 2 DSPs will be in series then). Regarding the outputs, you'll need to route DSP B out 1 + DSP B out 2 both to ANA1 (analog output 1) and connect this output to the fx loop return.
I assume your amp uses +4dB line level signals, so you'll need balanced cables with XLRs connectors on the Eventide side and unbalanced 1/4" jacks on the amp side. The User Manual explains the wiring for balanced to unbalanced applications.
all the best
I