48v bldc self balancing controller design

Depends on who wants to help and how much they'd charge you - or if you look at it from your perspective, how much you're willing to pay.

The reason it's asked is that you indicate to have little knowledge about this part of the engineering effort and want someone to help with it. You can then do two things:
1: Learn how to do it. I predict this will be a painful exercise and will take a long time and meet a lot of frustration along the way. Designing a high-power driver for this application is specialist work; if you've never done any serious electronical engineering, it's going to take you a lot of time and effort to master it.
2: Get someone else to do it, but obviously, most people don't work for free. It's a quicker route to success, but more costly financially.