Just some comments first on the components you have chosen - are you planning to freestyle, race or both? The Karearea talon is designed as a race frame and the Steele motors are designed as freestyle.
The runcam is about to release a v2 of the split shortly, it fixes some of the minor issues with the first version.
The HQ 5x4x3 are commonly used as a freestyle prop and perform great but are brittle. The Dal 5040v2 is a clone but made from much more durable polycarbonate (Dal poycarb is legendary!)
If you stick with the talon frame, you’ll probably want a 4 in 1 esc as addiing individual escs to each arm defeats the purpose of a vertical arm frame a little (Joshua Bardwell did it but seemed to regret it). I hear good things about the speedix 4 in 1 for this scenario.
I only really know betaflight in terms of flight controllers and my favourite here is the Matek F405 which is well priced and appears very reliable.
For VTX the matek vtx and Unify HV are good and include adjustments via OSB but there are a raft of budget ones coming our that may rival them (on paper at least) for about half the price - e.g. the new AKK one.
Just my opinions on how I’d build but depends largely on your preferences and objectives. Good luck and have fun. I much prefer building 5" quads as they are less fiddly!