Do I ask an established business to collaborate on a new product?

I have developed a modular frame design for displaying photos. This has many opportunities for multiple markets and a variety of sizes, color, and finish options. I am currently stuck in trying to determine if this concept would be affected by some existing design or utility patents. I am not finding the USPTO site very user-friendly and haven’t been able to identify the correct classification. I have not found anything similar to it in the marketplace based on internet research to date.

I have identified a company that produces some similar hand-crafted items and also prints photos & photobooks. They have the infrastructure and marketing base needed to launch this frame + photo prints as a “total solution” product and it seems like it could be a good collaboration.

I would like some feedback on the best way to proceed – these are some of the options I have identified:
1. Hire a patent attorney and fully vet any existing design and utility patents that could interfere with bringing this frame to market.
2. Approach the company I have identified for collaboration and pitch the frame concept to them, ask for their help and expertise in reviewing existing patents and tweaking the design for full production…….should I have an attorney lined up for this process?
3. Approach the original co-founders of the photo & photo book company I have identified and ask for advice on how best to proceed (they have since moved on to formulate another company)?
4. ???

Thank you!