EDIT- Edited as requested to be less of an open-ended question. That said I did receive some very useful advice. I contacted our local PHP meet up who passed me onto a local developer. Also, since countless hours on PPH, Upwork and the like, I discovered I needed to be much more focused in terms of my brief from a technical stand point.
Question edited as per below:
First a bit of background info - We have a project that's been dropping down our to do list for almost a year. It's an internal project, one I'm keen to get live. I'm personally coming to you from a content stand point, and without a website to work with, I myself am stuck. Our internal developers are currently far too busy with client work - in our daily standup, their sprints are always full week to week so I wouldn't want to take them off projects they're currently invested in.
This has therefore lead me to look for a freelancer that I can outsource this one project to. There would be a possibility for more work should this one go well, however the difficulty I am finding isn't getting hold of a developer keen to do one-off projects, but finding a quality developer.
As I am not a developer myself defining quality may be a little more difficult - but from the feedback I have received from our devs here, it's how clean the code is, the methods used to build the code, the documentation and the like. I now have a four-page PDF with our requirements which has been super useful. This is to ensure quality and to allow my own developers to jump into the code in future.
I've tried - People Per Hour, Upwork, Elance, Twitter, LinkedIn, Toptal and Codeable, all to no real avail.
PPH - Here I had the most 'bids' on my job, but most very cheap and the example sites didn't look good in terms of design nor code. I should mention I'm willing to pay for quality.
Upwork - Much better than PPH in terms of quality, but after speaking with some of the top-rated developers, as soon as I handed them our more technical requirements a lot said 'I use html and CSS, I don't touch SASS or Git or Laravel' etc, which doesn't fit with our methods here making it more difficult for us to make future edits and keep our quality high.
The other sites - I found either had too much spam or similar to PPH.
The best response I had was to contact our local PHP meet up and now I am in talks with a local developer who said all our technical requirements are as expected, no problem at all. So this is a positive lead.
So my questions
I now have a list of technical requirements from my own developers. As freelancers I understand this may not be something you would expect, but would you find it useful? Does it help bring clarity on the project?
With this project being a fair investment, there is a sense of trust between client and freelancer. How can that trust be strengthened? Once again does my list of requirements help if the freelancer can agree to these?
While I understand most freelance developers have their own ways of doing things, is there a way I can make it clear that I want my site built a certain way without putting anyone off? It's like asking for a baker to make a cake and giving them the ingredients.
More off topic - should developers be able to build from design concepts or is a pixel-perfect design always preferred? This is more of out of interest since I've had varying responses to preference. I've only supplied flat-PDFs so far before committing and some have said that's all they need, others have requested my PSDs.
And finally - is a freelancer even right for what I am looking for? Am I asking too much of one person? Should I be looking at going to an agency instead?
Any help as always greatly appreciated.