Hi Martin welcome to the forum.
If you give the guys an idea of the table size/working area you are looking for they will be able to set you on the right path, also go to the build logs and have a read, i am a noob to so can't offer much in the way of assistance but if Jazz pops in he might have a better idea if your ally frame is going to move following welding, you are very fortunate have the facilities you mentioned and i can't see a problem but others know better, are you living in a detached property ? could get a bit noisy.
Good luck
Mike