We've obviously PM's back and forth quite a bit. The takada, you got a great price on so definitely support that purchase!
As for everything else, just let me know what you need. I'm a Vendor for Fast Intentions so I can answer any and all questions having to do with their products. Have owned two of their exhausts (G37 and now Nismo), have been to their shop for a full week in Simi Valley, CA to see how things are built. Can't speak any higher when it comes to quality of their products which is why you really don't see me advertise for any other exhaust even though I can get pretty much any exhaust available for our platforms.
If you do LTH's, you won't need cats/tps since they completely delete the cat section. We CAN put 100cell cats in the end of the headers for you.
Suspention, like I mentioned before, its all up to what you want to spend.
I can offer great prices on any brand. BC Racing is a great coilover for around $1k, which you find is a commonly used coil on these forums. Stance coils give great adjustability but a horish ride quality. For $1500ish I would say Tein or KW V1's. Around 2k you're getting into KW V3's and "edfc" options for Tein.
Keep in mind, you'll want atleast a rear camber kit, if not front camber arms depending on how low you go.
You know you're more then welcome to PM me anytime on here, or add me on Facebook>
Personal page is Lance NextLevel Perf, biz page is
www.facebook.com/nextlevelperf