Not sure what the best way is. Portals are garbage.
Fiverr's a scam. Users make fake reviews by creating fake accounts and processing 1 time jobs through them. When there is a problem in the project (like freelancer can't follow instructions or read English) the project is cancelled and buyer is unable to leave review. So all problems where freelancer didn't make it past the first milestone or the client was refunded are not reflected in reviews. This results in a LOT of 4.5+ star freelancers who can't code their way out of a while loop.
In addition to that, Fiverr has a "no refund" policy from the perspective of if a project is cancelled and your money is removed from escrow, there is no way to get that money back into your bank account. This is per their terms and conditions and i've tried myself. So imagine only finding 1 fiverr contractor that you thought actually was going to do what they said they were going to do. And say the project (or first milestone) was $1,000 and you deposited the money in escrow to get started. If something goes wrong with that freelancer, you will never see that money again in your bank account. Fiverr will list the funds as an available balance on your account but will not refund it back to your card. Now your stuck trying to find a freelancer on fiver just so you can try to get your money back.
Upwork has similar problems:
Reviews don't match work effort. When there is a problem in the project (like freelancer can't follow instructions or read) the project is cancelled and buyer is unable to leave review. So all problems where freelancer didn't make it past the first milestone or the client was refunded are not reflected in reviews.
And the answer isn't in paying more either. The year before last year I did a test coding project where I hired 4 developers that fit the minimum qualifications for the same job. They all got paid what they asked for with the highest charging $120/hr. The top two devs had to be highly rated with lots of billed work on the portal while the bottom two could be new or only have a few reviews (add had to be positive).
The top two most expensive provided the worst work and delivered after the deadline. The least experienced and lowest priced developer was the most responsible, most communicative, and oddly enough produced an decent final product given his experience. So the saying "you get what you pay for" is complete BS from people that just need something to say.
Agency fee range can get far beyond what you posted. The main problem with agencies is over-paying and being deep into expense before realizing you'be picked the wrong agency. Even if you picked the right agency in the since of getting quality code written, you need to have a much higher budget for the project. This way the CEO, secretary, office manager, assistant manager, project manager, accountant, cleaning lady, phone company, etc can get paid well from the project....on top of paying the people that actually write the code!
I feel like the best option is to hire local help. Start looking by joining local groups or visiting colleges to find people passionate about your needs. Don't go there advertising your looking for help. Just observe and mingle. Spend enough time to learn who is passionate about doing x in the community and then offer the people you meet that are qualified a contract job with detailed specifications. This works sometimes.
If you just want to buy a theme, check out themeforest.net (envato market). I'be bought stuff from them and never been too disappointing. The only thing I really ever have had a problem with in their themes is they are almost always bloated (include way more code and libraries than what is needed to accomplish your needs). Do if you just download and deploy you end up with tons of extra junk running that you might not need or want. With time you can remove what you don't need to make it lighter and still have all the features you were looking for.
