Originally Posted by douzzer

Pretty good priorities, IMO. Alas there's no off-the-shelf roll bar/cage yet.

You left out some high priority bandaids sold by or pending from Mantissport: accessory underdrive pulley, sump extension, and (not yet available) crankcase breather oil separator. I have these at the top of my list, actually.

You left out coil-over suspension. Without it you'll be limited in various ways.

If you do the engine bolt-ons your peak thermal waste rate may rise significantly, and as a consequence you may want the third radiator, either placed in series with the existing ones (an easy mod) or set up as a dedicated oil cooler (more complicated, but probably superior, and Mantissport apparently has a kit).

You don't have any aero (downforce) tweaks on your list. I'd assume there will eventually be some appealing options there.

Oh, and if you're budget-constrained in any relevant way, I'd defer engine swap until later, much later, if you do it at all. Remember the true dry sump engines aren't plug-and-play options (and cost a fortune besides). Ken S is up about 50 RWHP with bolt-ons and firmware, and what he did to get there, anyone can do for a fraction of what it costs to do it with an engine swap. And he's still running with OEM intake plenum and accessory pulley, so there's more to be had and cheap too.