I have met Jon a couple of times, and was very impressed by his presentation at the Paid Search optimisation (think that was it anyhow). Certainly one of the people I would expect a lot of UK based search marketing profs to be adding as well.

My experience with the other two is limited, particularly Ciaran, however Will Graham speaks of him very highly from his days at RBI. Rob as well seems to have been around for ages. Is he really 24. Better start packing my bags then…..

Here’s my suggestions:

UK:
Jon Myers - Head of Search at MediaVest, been in the industry for donkeys years and probably know more about paid search than is good for him He is respected by “old” and new generation of SEOs/SEMs, which is rare, and is a regular speaker at SES.
Ciaran Norris - Head of Search at Altogher. I recon Ciaran is UKs answer to Rand Fishkin, well he might as well be working for SEOmoz as he blogs and comments enough over there. He is also a really good speaker and has a really broad knowledge of both SEO and Social Media, in fact I think Ciaran is probably one of the best SMOs in the UK. Ok his head will explode now.
Rob Kerry (evilgreenmonkey) - Ok this guy is freakin 24, he’s been a editor at Search Engine Watch, currently editor at Sphinn, he has been speaking at conferences since he….ehm started talking at 2 He goes to about every conference there is and likes to mingle. This is a guy that doesn’t become too “big” to speak to people and although he can be a right opinionated donkey, he knows his stuff. Hopefully he won’t see this as he will never let me live it down, I usually just insult him.

anyway, that’s a few of my suggestions, I could go on and on, really should get back to work now =)