Amazing how many people can't read isn't it... Either that, or they all plan on flying from Delhi to take your brief.
OK, I'm not based in London, but considering the nearest bid you've had so far is from Romania, I thought Manchester wouldn't represent the 'ends of the earth'... I've been working remotely for 4 years now anyway, so I'm pretty well versed at taking long-distance instruction. - I'm also comfortable with Skype / The Phone. Whatever you need.
I don't have a lot of 'characters' for this pitch, so I'll get straight onto the 'shameless self-promotion' part.
I've been developing PHP based CMS for 15 years, I'm a 37 year old dedicated freelancer, not some undergrad playing at business. I specialise in User Account / Profile-based framworks and can distribute in CSS3, with a whole host of HTML5 widgets.
I know WP very well, but for something like this, if you're going down the 'established' CMS route, I think Joomla will serve you better, it's MySQL querying architecture is much more refined than WP, making it better for sites that need to provide mission critical services. It will also prove to be far cheaper, and offer a much better time-to-market, than something like codeigniter. You're much better off saving the raw code for your custom functions, not wasting it all on platform building.
As you know, there's a tonne of module extensions that will handle all of your requirements. With this in mind, I've quoted low. No more space left. Let me know if you'd chat