Thanks guys, they are a mixture of rims actually.
I put this same thread on another forum which seemed to cause some conflicting views....
After all that though, there's a chance that my rear hub is shot (will find out from the LBS today.)
If that is the case, I'll delay the build by a month and just get a new wheelset otherwise I'll just run with them as they are.
There's no issue with clearance, my Bonty 2.25's have masses of clearance around them, I'm pretty sure that even a 2.7 would be fine (although I suspect that my legs wouldn't be

)