Since you mentioned you're raising a seed round, I strongly suggest not using an investment banker. At the seed stage, VCs are investing in you more than your business—putting a banker in the middle will do you a lot of disservice. IBs are typically used for Series B and beyond.

I also noticed that you call yourself an engineering services firm—typically services companies don't make good VC fundable businesses. If you have a product that you can spin off and raise money for, that might be more attractive. Happy to chat in more detail about the fundraising process if you wish.