Longterm Wordpress Website Optimization & Maintenance

We run a motorcycle website in Europe on Wordpress and Yootheme with 80 to 200K monthly visitors. We have been working with a one-man SA developer for a long time now and prefer to keep doing that. But, we need an upgrade for 2 main reasons: higher level development skills and better communications. For that we're now looking for a medium (~2-10 people) Wordpress company to run our 2 websites. Small enough to not having changing account managers every month, large enough to have someone available at different levels of work. We will need a few hours each month just for the site to keep running and having the (now South African based) server working smoothly, with normal maintenance and a mail server. Preferably we'll set a fixed fee for that. Apart form that there's always things that need developing, fixing or upgrading on retainer basis. We work with the idea there's responsibility at the developers side: if all is built ok, we shouldn't have any problems. Idea is the server is always up, but we understand there always can be unforeseen problems. Point is, when the site goes down on a Friday we can't wait until Monday morning. That doesn't mean SLA's and respond times, but taking responsibility when there's a problem. We've never been down more than a few hours. Then there's adding and removing new and outgoing ads which is a bit more simple. That's where the 'small company' with junior developers comes in, since it's a bit of a waste having toplevel developers do that. Apart from that there's some projects, for instance now priority would be having an upgraded ads system (now: Advanced Ads) and we're looking for help improving our newsletters (ACYmailing). We also can always use SEO recommendations, but they need to be different from the normal SEO, since we're not looking for conversion but just for more readers. And then there's always a few plans or upgrades on a regular basis where your input is very important: if you come up with a great idea we will very probably say yes. We're in all this together, it's OUR websites! FOR NOW: we would like to 'testride'* a new partner with a small project concerning what we call P1/P2/P3: we have trouble controlling the position of our first 3 articles on the frontpage in Yootheme. We want to be able to fix one article on one fixed place for a fixed time, while the others keep their normal order when new articles are loaded. *we're motorcycle riders ** don't use Ai to write proposals. We will know.