I don't want to be discouraging, however, I feel like a market place looking to take on established players, isn't really going to work, if you are 'learning as you go'. Even the most likely challengers failed, despite having significant experience, reusing existing platforms, and having a LOT of experience in their team.
I think if you want this to work, you need to establish firmly some pillars in your plan. One should be security for example. This covers security of your platform and data. Security of your payments and of peoples goods, whilst transacting, and of peoples personal information. The fact you ever thought routing funds through an account you had any access to directly, rather than through an established mechnism like stripe is wild to me.
Do you have a business plan? Understand your market and how big is it, or understand fully the costs vs revenue you are likely to be working with? Does the return seem worth it? Do you have a marketing plan? Budget? Funds ready to fund all of this?
What security and business process systems are you going to align with? Is your hosting environment going to meet a particular security standard? ISO27001? PCI?
I can be one of your 5-10 if you'd like, depending on what's involved. I feel like you are quite a long way from that yet though, and to be honest, I'd feel a lot more comfortable giving you my time, if I knew you had a properly fleshed out plan.

