Hey dude i've recently done this, bought all the parts myself and gave to a local engine builder. It worked out a better spec than Race Tech and Tuning Developments 'Stage 3' engines, and cost less. With the additional being headwork, and ARP studs. He highly rated maxspeeding rods which are only 200 quid and come with arp bolts. They might be chinese but hes used them in 400bhp Vauxhalls. Some of these arent 100% needed but im a beliver in 'modding ahead' build it safe and future proof. If you want 300bhp then build it to take more and dont run it at 100%. Found Wiseco flat top 74.5mm pistons new on ebay for 400. ARP head studs are actually cheaper than ARP bolts, just an extra couple hours machine work and your engine builder will hate you! Haha. Advised for anything over 300bhp. ARP main stud kit. Advised if wanting 300bhp. Got crank seals, timing belt kit, valve stem oil seals, magnetic sump plug, oil filter housing gasket, 0.5mm headgasket, water pump, fuel filter, oil pump, throttle body gasket, 3 oil filters, all from Idworkz. Go OE genuine for the seals, couple quid more thats it. There is no point buying a full gasket kit! You end up with a load of CT9 shite! Make sure you go to a very good builder, that will make all the difference. One who weighs and balances the rods and pistons, and balances the bottom end assembled. Believe it or not thats extra from Race Tech according to their site.