I've got an 08 3V with a Paxton 1200 non-IC. Before I filled my engine full of metal last year, my car made 508 rwhp STD with this blower at 10 psi, IMRC deletes, Comp stage 2's, JBA shortys, FRPP x-pipe, and a couple other small things I can't remember. That dyno run was on a 104* day in Sacramento at AED.
The non-IC blower will make plenty of power, especially if you have the right supporting mods. However, it's very difficult to tune, because the IAT's have such a large possible swing as opposed to the intercooler model, so your only safe option is to tune it very conservatively.
I also road raced this setup through the summer and fall of last year and only went into failsafe mode once on the track. These engines tolerate lots of abuse (aside from lack of oil as I found out), but for better longevity and safer levels of performance, you want a charge cooler asap.
Also, if you install the non-IC kit, I can assure you that it will be a long time before you intercool it. Once you have the the boost and power gains and all seems well, you'll put it off and put it off and before you know it years will have passed. If you buy the non-IC kit, do yourself and your engine a favor and either pick up the Paxton air-to-air kit at the same time (obviously only if the non-IC kit is a smokin hot deal) or engineer a custom intercooler to install along with the Paxton.
Almost a year later, I'm still trying to decide what to do as far as charge cooling, all because I found a too hard to pass up deal on this goddamn non-IC Paxton!
The meth injection idea is gaining a lot of traction with me, but I still want an intercooler, regardless of whether I go with meth or not.
Finally, as for a custom intercooler, there are definitely options, but very little info online for our specific setups. There are plenty of universal intercooler manufacturers, but that's as far as the info I've found goes. Aside from the right brackets and hardware, you'll need to measure out, find, and order plumbing that will adapt correctly. Then you'll need to tune for it. Also, I'm not sure whether a 2nd bypass valve is needed, but the Paxton kit most definitely includes one. What would be really useful to have is a detailed cut sheet of all that is included in the Paxton kit, along with a step by step DIY install guide with photos. So far, I haven't found enough to convince me to start trying to piece an intercooler kit together myself. Good luck with whichever route you choose.