Lydden is reasonable even if you don't have trackside access. The hair-pin is good for some slow speed or opposite lock action, but for the faster speeds you want the bottom of the hill near the pit exit. TBH there is only a small section of the track that you can't see all the time, so it is a great spectator circuit with nice short laps.
I have loads of shots from Lydden on my web site E30 NERD
Infact I'll be at Lydden on Monday.
Mallory is a longer circuit, I've only been there once. I found the best as other said was Shaws hairpin. At shaws there are some other nice features such as the house and the tree etc that can give a nice backdrop. However, from near Edwinas you could get a good view of the cars going up the hill through Lake Esses and onto Shaws in the distance. At Devils Elbow you can almost lean out above the cars!! They get very close. If you have to walk around the outside, prepair for a hike!
Have a look at the etracks web site if you want a feel for the layout