Hi
Before we begin that picture is beautiful! Dam that crank is light, I love the look of new bits.
I'd go oversized valves that way you don't need the lift (as much) as lift is just another enemy, spring wear, breakage and also rpm. Your there may as well do it right! My valve guides were 0.495 and 0.493 outside and 6 mm inside of course. Knock yours out and measure buy to suit! Ask for m52 ones otherwise they will send 7 mm guides.
But don't buy cams yet either, you need to do a practice build with existing camshafts to see what will fit!
No point having massive cams if you just end up hitting Pistons with valves!

As for timing case, go either late m42 timing guide, small oil pump.
Or m44 timing case timing guide, large oil pump but you need to make a bracket to hold crank sensor.
Cheers Rohan