Take a look at this;
What is your purpose;
Is there something you want to do which existing equipment does not do?
Is it that the available equipment is too expensive?
Are you just looking for a challenge to meet with an arduino?
You are going to be hard pushed to provide more features than what is commercially available. It is possible you could provide some features at lesser cost but they will be relatively limited and require a lot of effort. If you want a challenge this would certainly fit the bill.
If the core objective is to support a band I would find ways to make money to buy kit and bootstrap towards being able to buy better kit.