Regarding PR Spitfires, here is a good site on a quick rundown of the various marks.
Invasion stripes were used both during and after the D-Day Landings (Normandy invasion of June 6th 1944). Since you are converting a Mk.I it is highly doubtful it was still in service after four plus years.
Bubble canopies, I'm not sure if they were utilized for photo recon - at least I don't recall seeing any photos as such. I do know they did have special ones made with a bulge on either side for better viewing. Check out this conversion review. Again bubble tops appeared late in the war starting with the Mk.XVIe.
All that being said, it's up to you if you want to mix and match things that are not historically correct - and if GB leader is fine with it.
regards,
Jack