Startups usually consider outsourcing - that's one thing I can suggest. You can include an outsourcing plan together with your business plan over the next few years. Some tax firms outsource their tax preparation service to BPO companies that cater startups, small or medium-sized businesses.
How would you like to start, by the way? Do you have investors already?
If you are looking for what criteria a tax firm catering to small business should have, then here are a few comments/questions from my clients:
Are they an experienced CPA?
Do they know the latest tax laws?
Do they understand what it takes to run a small business?
Do they have what it takes to run a small business themselves? They want to know if you are like minded.
Do they offer upfront pricing with a pricing schedule?
Can I get them or anyone on the phone?
Do they have a reliable staff?
And the number one comment I hear- Are they trust worthy?
Good Luck with your new firm.