Registering with a Broker Dealer as an Independent Investment Banker (To "Outsource" Compliance & Regulatory)

Quick question - Helping my sister - She's an investment banker with a middle market firm, wants to go solo with some of her MD's. They don't want to go through a 6 month process up front to create their own Broker Dealer setup. Wants to "hang their licenses" with a reputable, comprehensive (tools, compliance, subs, etc.) Broker dealer that specializes in this - basically "outsourcing" the compliance and regulations to a specialist so they can focus on their core competencies of growth / servicing clients.

Any names you'd recommend??

Thanks!!