Hi Paul, really great to see you fulfilling the ambition. whichever direction you go will be great fun.
Ive owned various kit cars; bit of fun tootle around re-bodies like the DBR: mx250/Sammio Spider/wildcat E type and also driver focused models like Silva phoenix and Westfield.
You are at a difficult (but fun) point in deciding direction.
Im not familiar with the build and panels for the very beautiful DBR but it sounds like its a component/modular build like the Exocet and hopefully things have come on a fair way re kit/re body builds in the past few years.
The biggest issue for me with the re-bodies was that without exception they did nothing to improve the driving dynamics of the base car i.e. the base car was better to drive and more enjoyable than the kit albeit didnt look as interesting or characterful. Also they looked amazing when complete but took lots and I mean lots, of filler (I hate filler)/prep/sanding and repeat to make them look as perfect as you would want them to. Then deteriorated reasonably quickly with fiberglass crazing/flex etc. so bodywork maintenance can (not always) be onerous to keep them tip top.
All of mine were substantially 'professional' builds as I didnt have the time myself and then I did the bits and mods that time allowed.
Now all that seems negative, but... maybe if building myself from scratch, to my standards, with panels that did not require copious filler and body smoothing to achieve consistent smooth lines etc then it may have been different. I have friends that have owned/driven Wildcat/Challenger e-types and Hawk Stratos for years and (particularly the Stratos) still drive and look amazing.
The Exocet and similar 'driver' focussed kit cars are a different proposition as normally you are adding rigity/structure, minimal bodywork and panels designed for the new structure (less horrible filler) and these generally improve the driving dynamics. Upside great to drive, downside often not as comfortable, weather protection, possible lairy handling depending on how they are set up etc.
Having just re-read my post I dont think Ive added much value to your dilemma
I would say and Im amazed how many kit builders/prospective owners dont do this (me included in the past), get a decent drive in completed versions of whatever you are considering and not just the makers show car. You are probably a step ahead of me on this one but, a little like CW watches, there are usually super enthusiastic owners groups and forums that someone will be willing to take you for a spin in their pride and joy as well as giving you the warts and all version of the build process.
Whatever you decide to do please keep us informed as it will be really interesting and fun.