Question Re Terrain, Scenery Addons

Hello,A quick enquiry,since the purchase of Fs9 a year ago I've mainly concentrated on gaining flight experience and buying Aircraft, hardware for spec etc, and I'm really only now turning my attention to add on scenery and terrain. Now, my local store are having a half price Flight Sim Add-on sale and suddenly lots of Add-on scenery has hit the shelf. So can anybody answer this because I'd have little experience of it1. Whats in the store is FSene Volume 1,2,3 FSGlobal Pro Edition, and VFR Scenery that covers the whole of Great Britain which is where I fly, also there is a VFR Terrain for Britain. So which one is best for terrain, if I get FSGlobal would there be no point in getting the Terrain VFR for Britain, would there be a difference in quality, and can I run them both by deleting the Britain scenery for FsGlobal for Britain?2. When you install VFR scenery can you install terrain for that region on top of it or would the terrain also be included in the VFR scenery that I bought?Lots of questions, not really asked very well but I gotta get a general idea in case the only other Fs enthusiast in my town gets there first!Any help appreciatedGeorge Tyrrell