I mentioned the S or A trim head units because they are older and can be had at a much cheaper price but very efficient. Of course you could with a new v3 si and swap pulley for more power later one. Same goes for a used S or A trim kit. generally if you ship your head unit back to
vortech for rebuild they rebuild to the v3 spec now.
I had issues getting the 42lb injectors dialed in and jumped to 60's and it was piece of cake. So based on that reason my opinion would be to skip to the 60's if you don't already have injectors plus you'll have more room to grow with them later on. The 340 pump is good but you could get by with just a walbro 255 and no need to upgrade the fuel rails and lines with your power levels. You will need an adjustable fuel pressure regular, aeromotive's is nice, holley's is dog
. No gauges are mandatory but I would suggest a boost gauge and a fuel pressure gauge for piece of mine.