I've heard people say that the Palmer PDI-09 has the same speaker simulation as the Palmer PDI-03! PDI-09 is 4 times as cheap as the PDI-03, but then of course, the PDI-03 has a load box built into it.
Keep in mind though; if you use the PDI-09:
You CAN go pre-amp out -> PDI-09 -> mixing board
but if you go power amp out -> PDI-09 -> Speaker in, you capture the sound of the poiweramp (so presence etc as well) also, which makes it a lot fuller IMO. I can do a comparison if you're interested between PDI-03 (poweramp) out, pre-amp out and impulse.. It'll give you a good idea of the possibilities!