There is a bit about this topic under the antenna heading, I have read about both these aerials and the general opinion is that you made the right choice by going for the 827. Would have been my choice to and am sure you will be pleased with it. As for the gp kit, both would be better with one-for gp.
Al
---
Al -163FB777 - N.Wales, UK
Kenwood TS-480SAT, RCI 2970 dx 150, Astatic M6 or Turner +3b mic, A99-Base
1/4 wave whip when static-mobile