I've spent a considerable amount of money on gadgets over the years and, while it's been fun and educational, I suspect the money could have better spent. Of all the equipment I've used there are only two reccomendations I could offer; The first would be an A.E.R. amp which in my opinion is the best accoustic guitar amp range on the market. Secondly a £5 "feedback-buster" which has got to be the best value-for-money piece of kit ever. Provided you've got a decent sounding guitar and a measure of ability you don't really need anything else, although I agree that a decent muted floor-tuner makes sense.
This from a man who has terminal gadgetisis and is currently looking for a gadget that will house all my gadgets! Maybe the bin?
I wouldn't want to deny anyone the right to try/buy everything in their quest for that perfect sound, it's a journey most guitarists make, but I believe you'll end up where you started, but poorer.