Full Backs, Center Backs, Both at the same time?

Today I see Doogie again talking about CB's playing Full back positions.

I'm wondering if we actually have any full backs who would be in the modern mold shall we say. In otherwords joining in the attack, beating a man, getting a cross in etc.... in the Evra, Baines, even Alonso last season.  Bap is described as a CB who can  play right back.....Ream has good technical control for back up left back?   and Teirney I don't know about yet.
In todays game full back support in attack is a requirement IMO. Something we were lacking last season also.

What do you lot think?

I just want full backs that can defend

first and foremost they have to be able to defend, but if we play 3 in midfield it means that the fullbacks have to push on to provide the width. If Baptiste and Tierney play as the full backs theyn they strike me as more defensive. In an ideal world you want a full back to do both but as Dazshack says we need to tighten up our defence first.

I more in favour of defend as a team, attack as a team but with OCs system, and to a lesser extent Dougie's the game gets stretched which in recent seasons has made us vulnerable, especially on the break.
I understand that the natural reaction to this is to go "back to basics" i.e. have defenders that focus on defence but Terence is right in saying that they need to contribute more than that in the modern game.
However, I'm sure that both OC and DF's systems would work fine if we bossed the centre of midfield and controlled possession but unfortunately we haven't been able to do that since Holden was first injured - and our results have suffered since.

I like to see full backs getting forward. I think Alonso was a pretty crucial part of the attack last year.
Equally, I hate them forgetting their fundamental role - defending. We've had a lot like that in recent years - Gretar Steinsson was probably the worst for it and he wasn't even good going forward.

Hayden White could develop into a good FB - fast as a whippet that lad.