Fast growing, UK B2C SaaS doesn't really give me enough information. The most critical piece of information is your revenue/growth rate or valuation. That's going to determine both who your potential acquirers are and who the best type of firm is to help you sell. M&A firms tend to be broken in...
This is loaded question. Give anyone of us here with that expertise a call to help you out better and in more depth. Humberto Valle Unthink Strategy