No PEC rods are utter shite to be frank, if you are staying on hyd lifters then I'd personally prefer stock rods with ARP bolts. I've seen so many pictures of failed PEC rods where the cap has failed - they have a counter bore and it leaves a very sharp and weak point on them - compare it to any quality rod and the caps are night and day. I've also been told of oval big and small ends not being that infrequent... imo just wouldn't touch them.
Carrillo, Robson, Saenz, Arrow etc all good rods - gonna be £1k+ though on average.
Regards cat solids, yeah the finger kit is for 8.5k+, but then you have moved in to another league again. You'll need a big valve head for the airflow for those sort of rpms and cams, without then the head will be a choke and so the solid setup will be a big expensive waste. Also big valves require an 84mm bore so it's not really something you can upgrade to later or you'll have massive repeat expense in new pistons and reboring block etc. Those rpms going to 9k should really be on a dry sump setup too. Oh and the crank and rod geometry is terrible for those rpms, so you'd be looking at the 90mm stroke Maxi crank and 150mm rods - again, properly tuning these is NOT modular! As for induction, also need to be 50mm Jenvey setup, no chance a 45mm setup would service the airflow on that spec.
In fact 45mm tbh is imo too small anyway if you're looking at vvt-delete cams and pistons, best off using 48mm.
Who is building it and advising you? F4R tuning should be a holistic approach because essentially the engine when stock is so wrong for high rpm, that unless you define the spec and budget it'll either not deliver or be cost prohibitive to upgrade because it'll involve scraping so much of what you have already bought. - What's the BHP target and budget?
If I had to stab a guess at the most reasonable setup given what you've said, then the 432 cams (403 non-VVT equiv - they'll make peak around 7500rpm) and hope they clear the pistons - if not, use Wossners (and now instead I'd use 433 cams) because at least they have a mk3 crown design. ARP bolts. Port the head (tbh mostly just exhaust port work at this level). Use 48mm Jenveys and along with your ECU will work without VVT etc. Chuck an R3 manifold on (need to mod your system because it is longer and finishes further down the car), maybe a Ktec but of course unproven at higher power levels presently.
The weak points in above
-non tagged bearings, but without expensive rods and valves probably a comfortable omission to make given the cost to do
-2-piece valves, as above nothing hugley expensive to lose other than the Wossners
-oem rods, as above really
If you want to address the 3 weaknesses.....then they need doing as 1 and it is a lot of extra expense.
But it'll give you (hyd lifter exception) everything setup for 8k reliably. So it would allow you to run maybe the 431 or 434 cams. Tbh this is the quandary I have, my feeling is 434's though are going to be too close to an 8k peek and thus the cross over point into a solid profile (not the finger followers, but Cat's solid lifter with lash caps on the valve stems), therefore 431's I reckon will do best on Hyd's.
I wouldn't run 431's without the rods, bearings and valves etc - hence the 432/433 suggestions per last para.
In fact...... why not look at the R3 230cv kit, uses iirc OEM rods but ARP bolts, of course high comp pistons (still a 3-ring design), 230 spec cams (I can tell you from having measured them they are 298/292 with 11mm lift). You'll need a bit of spit and polish on the exh ports but other wise it's the RS version of what I've suggested earlier via the cat/wossner parts.
Only thing is the 230 Cams are designed to run vvt - either buy a better ECU (SCS Delta 800 p'n'p) or do a twin exh pulley mod to it.
@Northloopcup can give you all the info on the 230 kit, plus he's been around mk2's for so long I'm sure he'll know what's involved on putting an exh pulley on a vvt inlet cam.