No prob mate
I'm in the exact same boat at the moment, whist my 5 is away getting painted I hope to start on my engine.
I will be keeping it carb (modded), running a 285 cam, T25 hybrid (through experience the T25 hybrid is my preferred choice, not necessarily the best depends on what your driving style is) front mount (behind bumper), ported and polished head, and forged interals so I can hopefully run big boost safely. It has to be done right because it's going to be my every day car
Your exactly right though, whist the engine is out you might aswell give it a rebuild to save time and cost in the future.
Have you also thought about just building a bottom end from an old block and keeping your car on the road at the same time? And if your engine is good, why not keep it as a spare and don't split the head and block just incase something happens in the future... You'll get a spare head and block to start from scratch for £50-100
I've never rebuilt a 5 engine if it's been running perfect, i'll take it out and swap it over with an engine I have built from an old head and block