Don't worry about height, look for what you like to ride (try other peoples bikes) - what you feel comfortable on and and what kind of riding you do will affect the choice most, but height + length tend to go hand in hand. I know tgs kids who are about 5'8" on silly long pythons, i'm about 6'2" and ride a 1025 leeson 660 It's all about finding out how you like a bike to feel, not how everyone else does.
wait 'til you've got more spare time, when we can get loads of us out on a ride (i.e me, simp, andy, byron, no bottle, lankyri, the down, jack, dan, borat, leon [wishful thinking], etc etc etc)
Chalkwell park really doesn't do it for me. I might come out and show you round, take some pics and what not. Depends who's out really 'cos the leeson is in no fit state to be ridden
Dual disc is amazing, especially on a mod. The onza calipers are surprisingly good, put a decent lever on there (even an sd7 would be fine) and a slick cable of some sort. Won't cost much more than £20 max and you'll have a pretty good brake
Was referring to the whole no hop, just tuck kinda thing, obviously the higher you go then it happens with good reason, but when it's on 2 foot walls it's not really necessary