Quickbooks Pro has enough features for real estate business, including flipping.
Just to give you a general idea on the setup. All expenses prior to selling the property should be classified as inventory, at least, create a category for acquisition, rehab, & carrying cost (you may break them down further into sub-categories if you'd like). Once the property is sold, move the costs from inventory to cost of goods sold (create the same categories/sub-categories as you have in the inventory). You can also set up categories to track for selling costs like closing costs, commission, professional fees, etc. Setup each property as Class then make sure you assign a class to each transaction. Create a separate class for admin expenses or any expenses not directly related to a property like office supplies, bank fees, office expenses, etc.
For tracking the money in/out by the partners, create equity account for each partner, money in as capital contribution, money out as capital draw.
By the way, Quickbooks online can be customized like dekstop version. However, most people stay away from it mainly due to its cost while others prefer it for convenience and mobility. Good luck!