Fitting upvc door frame

[Jamminjoe]

Hi
I need to replace wooden French doors and frame with double gazed probably UPVC. I've seen a few second hand that i thought could be good, so firstly anything to watch out for when buying second hand doors?
Second the origional opening is 2350mm high and most UPVC frames are at least around 2000mm. I've no problem in building a wooden frame for the UPVC frame to fit under but not sure what i could do to fill the gap above that. Could i render it? or use a fascia boarding? Any advice welcome
Thanks
Joe

[tim reeve]

Joe is there a lintel above? If not fill in with timber and clad with pvc, this will be fine.Hope this helps.