After looking at your ad and your stated goals (here and in the ad) I have a couple thoughts:
As it was mentioned re: the final product, this is especially pertinent to plugins. Selling a plugin is more of a continuing process than an “okay, we’re done! Next!” kind of thing. Our oldest products were originally written for VST2 and RTAS in OS9 for PPC and Windows 95. We’ve had to port them many times, for OSX, the PPC->Intel switch, AudioUnits, the 32->64 switch, VST3, AAX, and AUv3, never mind how C++ has changed since then, or the advent of HiDpi monitors. A plugin with a UI that uses bitmaps made in 2002 is the size of a postage stamp on a modern Retina screen. So, a product with longevity (i.e. a hope of paying off its initial investment) requires continual finessing. And it’s very difficult (which translates to “expensive”) for a new plugin dev to pick up someone else’s code, because there’s a lot of ways to skin this particular cat.
Next, there is a lot of stored knowledge for making cross-platform cross-format plugins. JUCE magically renders all the available formats assuming you have the SDKs, but there’s a ton of hidden shit that isn’t written down anywhere. Someone fresh out of school can probably make a plugin that’ll work in Live, but he or she also needs to own and be familiar with Cubase 9.5, ProTools 12, Bitwig Studio, and Logic at a bare minimum, and be capable of working in both Xcode 9 and Visual Studio 2017. Those five DAWs and two computers comprise a significant investment in both knowledge and money. I don’t even want to talk about FL Studio, DP, or iOS, or the huge amount of fun figuring out how to Eden-sign AAX plugins. The reason I bring this up is that you say you’re looking for a VST developer. At this stage in the game, releasing a VST2.4 only is essentially pointless. You won’t recoup your investment.
So, what you’re really looking for is a partner. If I actually had money on hand, I would look at buying one of the smaller companies. Some research on here and in KvR will turn up quite a few folks that have done the dirty work but are probably not seeing a return on their investment. (Usually because one-man shops suck at marketing. Hell, I suck at marketing and I’ve been doing this for 17 years. But quantity has a quality all its own.)
The reason I write all is that someone with the ability to make a multi-platform plugin soup to nuts from bare metal is a fairly valuable individual with a lot of knowledge equity, and you’re not likely to find what you need just with an ask.