Old Beige Mac, Can any older mac users help? Options

[subgenius88]

I picked up a 266 G3 beige all-in-one that was already upgraded w/ a 30 gb HD and 512MB RAM for $100. I've got 10.1 installed and all 3 PCI slots are available. I'm planning on installing a USB 2.0/firewire card so I can attach external CD/R and HD and MIDI interface, etc.> I have no experience using a computer for music. I'd like to use it as for sequencing and audio and will be primarily recording tracks one at a time. Can anyone suggest software I can use on that type of machine. New software typically requires a faster processer, but is there any way to pick up older software. For example, DP 4.0 I believe is the current version, and requires more than I've got, but people were using 2.0 or 2.5 back when the beige was a little more current. I've been thinking about adding a sonnet cpu upgrade, but I'm definitely on a budget. Any suggestions would be appreciated.