Having a trial version will probably increase your sales as well ....
I want people to have the visceral experience of having a physical professionally packaged piece of software in thier hands.
Sorta like the feeling ya get when ya buy an InfoCom game that you're really really into.
I highly doubt you'll be able to find a publisher. If you can't, just release the game as shareware and put box and manual printouts in PDF or PICT format.
I do have an LC with a Daystar 030 accelerator card.
Oh, I also have one more question to ask you. Will the game be in color? Will it support multiple color modes, like 4, 16, 256, thousands, and millions? Also, here's a little suggestion to drive up sales. Make an OSX version.